Garden Culture Magazine: UK 11

9 Foreword

11 Product Spotlight

16 TheHydroponicStigma

19 Food Act

20 Water–muchmorethanWet

28 TheProblemwithIron

32 U.K. Food Policy

37 Five Cool Finds

38 Bananas:AbusiveFruits

44 Clover

46 SelectingaGreenhouseManufacturer

50 Who’sGrowingWhatWhere

52 AnecdotalEvidence

54 HistoryofHydroponics

62 Powder to the People

64 WhatarePhosphorus...Potassium

68 ItStartswithaSeed

72 Or…aClone

76 LightMatters–part1

IN THIS ISSUE OF GARDEN CULTURE:

Sometimes we have to look back to see what is in front of

us. We all make mistakes, and hopefully, learn from them.

When we are children we learn from our parents, peers and

teachers - we must in order to survive. “Don’t touch the fire.

Stay away from traffic. Don’t talk to strangers”... and so on. As

we grow up, we have to make decisions for ourselves. “Who

should I vote for? Is this job right for me? Should I fear (or hate)

someone, because they are different than me?” Or simple

choices like, “Should I eat processed foods, or grow a garden?”

All these decisions are based on our belief systems, and the

fundamentals of who we are.

When I was a boy the apples I ate were sprayed with DDT (colorless, odorless water-insoluble insecticide, C14H9Cl5). We were told it was safe, but of course, it turned out to be poison. The issues today are no different than they were 40 years ago. Mega corporations tell us their chemicals are safe, that our food is safe - to enjoy another Coke, and shut up. Well, they are wrong. The chemical-laden genetically modified food is not safe, and the plethora of health issues that simply did not exist 100 years ago proves it!We need to wake up, and stop trusting mega corporations and our governments with our health. There are many things we can’t change, or have very little influence over, like war and global politics. But food is not one of them. Granted, not everyone can afford to eat only organic food, and in some cases it is not even available, but we can start by changing our purchasing habits, to not buy ultra-processed foods, sugary sodas, and so on. Ignorance and apathy are our enemies. It’s time to start giving a shit about what is happening to our society, and start making our world a better place for future generations.In 100 years, I hope that our generation will be known as one that changed things for the better - because if we don’t, Monsanto may be writing the history books. 3

Eric

Garden Culture™ is a publication of 325 Media Inc.

E D I TO R SExecutive Editor:Eric CoulombeEmail:[email protected] Editor:Tammy ClaytonEmail - [email protected]

V P O P E R AT I O N S :Celia SayersEmail:[email protected]. 1-514-754-1539

D E S I G NJob HugenholtzEmail - [email protected]

Special thanks to:Our writers Judd Stone, Amber Fields, Evan Folds, Everest Fernandez, Stephen Brookes, Tammy Clayton, Grubbycup, Shane Hutto, Theo Tekstra, Jeff Edwards, and Helene Isbell.

P U B L I S H E R325 Media44 Hyde Rd., Milles IslesQuébec, Canadat. +1 (844) GC GROWS w. www.gardenculturemagazine.com Email - [email protected]

A D V E R T I S I N GEric Coulombe Email - [email protected] t. 1-514-233-1539

D I S T R I B U T I O N PA R T N E R S• Down to Earth Kent• Maxigrow• Nutriculture DGS• HydroGarden• Highlight Horticulture

Website: www.GardenCultureMagazine.com facebook.com/GardenCulture twitter.com/GardenCulture

How It Works…Once connected to a reservoir the AQUAvalve will open,

and allow water to fill the tray to a pre-set level of 20mm.

The AQUAvalve will not refill the tray until all the water has

been used. Simple!

Watch the video: www.bit.ly/AP-valve

By consistently meeting their plants’ requirements, growers

using AutoPot achieve impressive yields, with less time

and maintenance, whilst reducing their water and nutrient

consumption. I honestly cannot say enough about this

system. It really was love at first grow.

I have been growing in Autopots for the past year, and

have been seriously impressed. Everything I have tried has

turned out amazing. Tomatoes, cucumbers, thyme, kale,

and lettuce all did so well, I decided to test out some new

plants. I cut up a piece of organic ginger, and buried them

2” deep. And 5 months later... I harvested over 3 pounds of

the best ginger I have ever seen. I now also have turmeric

and a grape vine, which are both growing quite vigorously.

There are several things that differentiate this system from

other growing methods.

1. AutoPot Watering Systems keep plants watered using

gravity pressure alone; no need for electricity, timers,

or pumps.

2. They are environmentally friendly, very little water is

ever lost. Some commercial growers have recorded

savings of up to 50% in their water and nutrient

consumption.

3. AutoPot uses patented AQUAvalve technology;

the only watering system in the world where each

individual plant controls their own irrigation, and

receives fresh nutrient-enriched water exactly when

they need it.

The Autopot Watering System is an ingenious set up for growing plants, and one that I can personally recommend to anyone. From acres of commercial greenhouses, to the little indoor garden in your basement or attic; Autopot’s simplicity and the results will impress even the most seasoned grower.

Maxibright NOW sells Sunmaster Compacts in 250W, 400W and 600W versions, providing even more choice for growers.

Find your local retailer: maxibright.com/where-to-buy/

The all new Hyper Climate Control is designed to thermostatically adjust

airflow (via variable fan speed) into your grow space on both warm days and

cold nights. As cold air can be detrimental to plant health during night cycles, the

Hyper Climate Control drops fan RPM’s down to a minimum to keep the plants

warmer, and maintain just enough airflow for effective carbon filter operation.

During warmer daytime temperatures the Hyper Climate Control will lift

and regulate fan RPM’s to maintain your digitally selected maximum ambient

temperature. Set two dials only once at the beginning of each cycle, and forget it!

· Extremely easy to use - Set and forget!

· Lowest energy use of any fan/filter/controller.

· Thermostatically changes fan speed/RPM’s.

· Constantly maintains optimal daytime temp.

· Slows fan speed to low RPM’s on cold nights.

· For use on digital EC HyperFans only.

Moonshine is a brewed plant biostimulant that is designed

to promote impressive plant growth, health and terpene

production.

Big Benefits:

• Over double previous root size

• Increased photosynthesis

• Faster maturity and increased yields

• Increased insect resistance

• Contains NO synthetic plant growth

regulators

• Contains NO silicone

To view the Moonshine video, type into

your browser:

http://tinyurl.com/MOONSVID

The Monkey Fan from Secret Jardin has two speed settings, is height adjustable, and easy to install.· 13Watts – 2200 RPM· Stays in position· Compatible with grow tent poles 16 - 19mmTo view the Monkey fan installation video, type into your browser: http://tinyurl.com/MONKEYFAN

TLEDs from Secret Jardin offer an affordable, efficient,

and versatile way of lighting your grow room. The 26W

TLEDs are available in (Blue) Growing 6500°K, or (Red)

Blooming (Red mix - including infra-red, 2100°K, and

3000°K LEDs) options. The TLED is 93% more efficient

than CFL lighting in terms of PAR per watt. Flexible

TLEDs can be hung vertically or horizontally from

grow tent poles

16-19mm using the hooks and clips

provided, or suspend your TLEDs

from the grow tent using traditional

methods, like Maxibright Easy

Hangers.

To view the easy installation of the TLED, type into your

browser: http://tinyurl.com/SJTLED

The Daylight 315 ballast system uses an advanced electronic ballast

to power the Philips Elite Daylight 315W CMH/CDM (Growing) and

Philips Elite Agro 315W CMH/CDM (Flowering) lamps for excellent

PAR per watt output.

Plants that grow under a full spectrum throughout their growth

cycle benefit from a more natural quality of light proven to prevent

stretching, and encourage higher quality growth. Culminating in

strong, healthy growth, and high quality yields.

Find your local supplier:

maxigrow.com/where-to-buy/

You can now use the DAYLIGHT 315 digital power pack with any reflector that has

an E40 lamp holder, by using the E40 to PHILIPS 315W lamp holder adapter. The E40

adapter is quick and easy to use. Simply screw the E40 adapter into the E40 lamp

holder on your reflector, then install the PHILIPS 315W CMH/CDM lamp as normal...

and you are ready to go!

Find your local retailer: maxibright.com/where-to-buy/

The Maxibright DUO uses Filp/Flop technology to

alternately illuminate two separate grow rooms

automatically when set to the 12 Hour Flip/Flop setting.

Or use the DUO 1 Hour Flip/Flop setting with two lamps

in one grow room to half the lamp heat, and significantly

reduce the grow room temperature.

Maxibright DUO one of the most versatile ballasts ever!

• Flip/Flop Technology

• Six Power Settings: 25W, 275W,

400W, 440W, 600W & 660W

• Surge ControlTM

• Soft Start Technology

• Fast Lamp Re-strike

• Dynamic Frequency Control

• End of Lamp Life Detection

• Short Circuit Protection

• Thermal Protection, Auto Reset

• LED Status with Diagnostic Feature

• Silent, Lightweight & Wall Mountable

• Runs HPS & MH Lamps

The Xpert 600W – is a low cost, vented, powder-coated metal

enclosure ballast with 600W of Genuine Power. The Xpert

power pack has a precision-wound ballast, a matched digital

SmartTM igniter, and is manufactured using quality components

from Venture Lighting. The compact size of the Xpert (L: 245mm

x H: 110mm x W: 120mm) makes it ideal for wall mounting and

grow room use.

Find your local retailer:

ma xibr ight .com/

where-to-buy/

As most of you know, hydroponics is an extremely productive and efficient gardening

method to grow almost every kind of plant imaginable. Yet, hydroponics seems to be, at

least socially, directly associated with the growth of plants that are illicit.

Why is this? After all, hydroponics,

from a scientific standpoint, is the

best way to grow anything for large

yields, and overall plant health and

vigor. Hydroponics also offers the

most efficient way to farm while

conserving water resources, as

most systems lose very little to

evaporation and mostly to plant

uptake, while the rest is recycled back

into the aquifer. Statistics from the now

defunct Progressive Gardening Trade

Association showed that customers

of most indoor gardening centers

were actually media gardeners, and few

employed water culture methods.

Some years ago, I managed an indoor gardening center that

had to tailor its very conduct around the stigma that leaned

against its very credibility. There was a company policy in place

that if anyone so much as muttered anything about any sort of

illicit plant, they had to be shown the door.

It was a don’t ask, don’t tell policy that left me giving advice on

how to grow food to a customer base that in my mind was at

least a large percentage questionable. Even though confident

many customers were in fact growing veggies, as they would

share them, I had bought into the stigma.

One day a nurse and her patient come to visit the store. The

patient is paraplegic, and his nurse is pushing him in. I’m almost

certain, stuck in my tunnel vision, that he is here to learn

how to grow something that may help alleviate some of his

discomfort. Although, I would like to help this man, I also need

to follow the law, and I’m immediately hoping he doesn’t say

something that causes me to have to ask him to leave.

He rolls up to the counter, and has trouble speaking clearly,

so we communicate through his nurse. His name is Tom Kojis.

He has Cerebral Palsy. He’s the son of a farmer with stubs for

hands. He planted his first batch of corn in 1972. He was the

editor of his local newspaper for many years. He operates a

CSA called Koji’s Produce. He’s got a lot to teach, but he’s

here wanting to learn how to expand his urban farming into his

basement with hydroponics.

Urban farming? Yes, his father who still

owns the farm, sublets enough space

to Tom to grow corn, but the rest

of the operation happens in his

modest fenced city lot - on a litany

of custom made benches, and in

4 greenhouses he has in the back

yard. An elevator will lead you

into his basement where Tom

uses a General Hydroponics’

Aeroflo to produce romaine

lettuce in the winter time, along

with a Volkswheel.

Although he’s been at it since the

70’s, Tom is always looking to improve

his gardening prowess, and since we met, has

designed and built many different hydroponic systems with

varying results. He operates 2 produce stands, and offers service

to his community in Waterford, Wisconsin - right from his front

porch, named Kojis Produce in 2005.

Tom is such a successful urban gardener that he has been able

to donate over 10,000 pounds of fresh produce to local food

banks, multiple years in a row. Tom’s ideas for the future include

expanding his reach into local restaurants that are demanding

better quality, pesticide-free produce to include in their dishes.

Tom has had to train all sorts of people just to lend him a hand

on the farm over the years, and this spawned the idea of someday

creating an urban farm/classroom environment on the site to

teach physically disadvantaged children and teens about urban

farming practices, and about Tom’s being able to overcome similar

hurdles to become the successful urban farmer he is today.

I judged Tom the day he came into the store, and unrightfully so.

Urban farming and hydroponic culture are the future of farming -

period. Its methodology is going to be a contributing component

of food security in the not so distant future. I couldn’t be more

overjoyed and thankful to have met Tom Kojis, and to have helped

him work through the innovation he represents today.

This is an awareness article, and an open apology letter.

Don’t ever judge a book, a customer, or a store by its cover. 3

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BUT...

Few involved in the chatter took time to read past the

headlines. Many assume this means that Californians can

suddenly tear out all the landscaping, and turn the entire

property into a vegetable garden. The law stops landlords

and HOAs from levying fines on residents for growing

fruits and vegetables, and otherwise punishing them

for doing so. But it isn’t license to grow your own just

anywhere. It sets specific limitations to protect residential

property values, and maintain attractive neighbourhoods.

First, it defines what types of housing it applies to for

renters and HOA members. The right to grow food

despite lease stipulations only applies to one and two-

unit buildings. Landlords cannot prohibit renters of single

family homes or duplexes from having a vegetable garden.

HOA developments have bylaws that govern common

neighbourhood interests, and AB 2561 removes barriers

to gardening for both renters and owners in appartment

complexes, planned housing developments, and

community apartments.

Secondly, this is not about urban farming. It’s a personal

agriculture provision. The produce grown under this

law can only be for personal consumption, though the

Sustainable Economies Law Center advises to check local

planning and environmental health agencies regarding

selling the harvest.

The language states that the law only removes restrictions

on private areas, and that such gardens must be in the

backyard. In appartments, food growing is confined to

containers in their personal space. A landlord can also

allow container gardens only to protect the state of the

property.

But the front yard turned veggie patch is not allowed. HOAs

can still levy fines for dead plants left standing, weeds, and

poorly maintained or unsightly backyard gardens.

This is a step in a very positive direction for many Californians,

but particularly for those living in food deserts and urban

environments. SELC sees this as legislation that will evolve.

Other states, and even other countries, should take note,

because food deserts are a huge problem across the US, and

the poor lacking access to good food is a global issue.

More Details: www bit.ly/food-act-faq 3

At the end of September 2015, California Governor Jerry Brown signed AB 2561 into a state civil code

law. Naturally, a host of blog posts, forum discussions, tweets, and hashtags erupted as word spread

across the internet. It is about time that government did something that makes it not illegal to grow fresh

food at home. And The Neighbourhood Food Act voids language in leases and homeowner association

bylaws to make this happen.

20 20

Let’s put it this way, water is much more than just

wet. In fact, with water, the further we look, the

less we know. As D.H. Lawrence said in his book

The Third Thing, “Water is H2O, hydrogen two parts,

oxygen one, but there is also a third thing that makes

it water. And nobody knows what that it is.”

Water may be the most obvious substance in our daily lives

and, at the same time, one of the greatest mysteries on

the face of the Earth. Water is everywhere and nowhere

all at once, showing up in the dew of the morning, and

reappearing as a fog rolling through the hills at dusk.

The character of water is one of grace under pressure,

constantly seeking its own level without prejudice. We

should be more like water according to

Bruce Lee, “Empty your mind, be formless, be

shapeless… like water. Water can flow, or it

can crash. Be water my friend.”

Water can be structured and energized,

and has a capacity to listen and remember.

Water has personality and is happier, more

productive, and capable of supporting life

when we provide the forms, conditions, and vibrations that

it likes. Water is the most sensitive substance on Earth, and

it has incredible capabilities when respected and treated

appropriately.

It may seem strange to give water sentient characteristics,

but it is so pervasive, fundamental, and important that there

is a limitation of language when it comes to its descriptions.

Besides, rarely, if ever, do we stop and consider what water

wants. It is collectively a passive substance in our lives.

Water expresses elegance in the grace of a babbling brook,

and power in the force of a whirlpool, or an epic surfing

wave at Jaws or Pipeline. For such a common substance, it

turns out we retain a surprisingly limited understanding of

its origins, abilities, and secrets.

Where does water come from? How many different kinds

of water are there? What is water, anyway?

The truth, on all accounts, is that collectively we don’t

really know water for what it is, or where it comes

from. We experience water more than we understand it.

Everyone knows the H2O chemical structure of water from

chemistry class, but you may be surprised to discover that

What is water, anyway?

modern popular science with all of its authority, expertise,

and experience has never actually seen a water molecule.

Major religions describe water as a seminal substance, and

at the same time destroying the Earth in great floods. Water

floated the Titanic, and sunk her at the same time. In more

ways than one, water is a vital conundrum in regards to

humanity and modern popular science.

Water has an unusually high melting and

boiling point. In some cases, hot water

may freeze faster than cold water. It’s

called the Mpemba effect.

Did you know there are at least nine

different kinds of ice, and over 80

different properties that are measurable

and able to be manipulated in water?

Water has a high viscosity, or resistance, relative to other

liquids. This also allows it to retain heat to help regulate our

weather, and be a great facilitator of sound waves.

Almost nothing behaves the way expected when it comes

to water, pressure actually reduces ice’s melting point and

thermal conductivity, and actually causes water molecules to

move further away from each other. Makes no “scientific”

sense - but so it is with water.

The strangeness of water is a result of its polarity, or the

expression of both a positively (+) and negatively (-) charged

side to its molecule, represented by the V shape chemical

structure seen in textbooks. The polarity of water makes it

capable of combining with and dissolving anything, giving it the

moniker the “universal solvent”.

One of water’s many roles is to pick stuff up and carry it

around. This includes delivering oxygen and nutrition inside

living cells, and carrying away the toxins, and also in creating

macro structures like stalagmites, or the Grand Canyon.

But it doesn’t always work in our favor. Water holds

things in a way to make them imperceptible, like an

invisibility cloak that prevents us from

seeing the substances held within. We

are mesmerized by its uniformity, and at

the same time unaware of its potential for

toxicity. Herein is the threat of runoff from

conventional agriculture and lawn care, and

public policies - like water fluoridation, and

chlorination.

Because water is a polar molecule and

opposite charges attract, water hugs itself

through a process called hydrogen bonding. We see the

influence of hydrogen bonding in clouds, the meniscus in a

glass of water, or the ability of water striders to walk on

water, creating an entire ecosystem called a neuston.

We owe our very existence to these anomalies of water.

Due to its distinctive molecular structure water exhibits

its greatest density and carrying capacity at 4°C with the

density actually decreasing below this temperature. This is

why ice floats on liquid water, which is relatively unique in

Nature, and quite significant. Imagine if water froze from

the bottom up, would life have survived ice ages on the

bottom of solid lakes?

There’s something like 1,260,000,000,000,000,000,000

liters (1.26 sextillion liters) of water found on planet

Earth. About 70% of the planet is covered in ocean,

and almost 98% of the water on the planet is in the

oceans. About 2% of Earth’s water is fresh, but 1.6% of

this freshwater is locked up in the polar ice caps and

glaciers.

Another 0.36% is found underground in aquifers and wells.

Only about 0.036% percent of the planet’s

total water supply is found in lakes and rivers,

which is still thousands of trillions of liters.

Relative to the mass of our planet, water is

the equivalent of the skin on an apple.

Water is life, but it also allows us to engage

life. To create 1 ton of steel it takes 272 tonnes

of water. It takes an average of 1741 liters of

water to make a 110 grams of hamburger. A

nuclear power plant requires 113 million liters

of water to cool its reactors… every hour.

In fact, one of the most important parts of food is water. Not

only is it required for plants to grow, but upwards of 95% of

plants and 75% of the human body are comprised of water.

Without water, we die. It is possible to survive for weeks,

even months, without food; but without water - we can last

only days.

Water is abundant, yet scarce. Almost half the world doesn’t

have access to clean water, or has to walk to get it. Most

people in the world rely on an average of 5 liters of water a

day. In the United States, on average, we use that much water

every time we flush the toilet.

The modern world is only just beginning to feel the economic

and societal pressures of peak water, and water security.

Business moguls are buying up aquifers and water rights.

Cities are privatizing their water supplies under corporations

that ban rain barrels, because they have contracts that say

they own the water before it falls. The UN even predicts the

wars of the future will be waged over water.

One of water’s

many roles is

to pick stuff

up and carry

it around

If you do the math, bottled water costs more than the price

per liter of gasoline. How can it be that something that

perpetually falls from the sky costs more than something

finite like oil that we are forced to drill from the ground?

Think about that for a minute.

Getting the most out of water in the garden is about more

than using it as a delivery agent for fertilizers, or filtering it

to remove contaminants. Water is a primary nutrient, and

using form and frequency, it can be structured to be more

efficient and valuable in the garden.

Misunderstood and flowing without form, many are

humbled, some are awed, but most in the modern

world are unaware of the wonders of water. Some have

even personified water with an agenda, as Tom Robbins

wrote in his book Even Cowgirls Get the Blues, “Human

beings were invented by water as a device for

transporting itself from one place to another.”

Water is infused into everything that we do, even our

language. We “go with the flow” when we cooperate,

or “blow off steam” when we get upset. Inexperience

is described as being “wet behind the ears,” and a bad

mortgage is described as being “underwater.” We say these

things without really even thinking about them.

My awareness of the uniqueness and the ability of water

first changed when introduced to the work of the late Dr.

Masaru Emoto in the film, What the Bleep Do We Know!?

The film documented Dr. Emoto’s work of showing how

simple intentions through sound, emotions, and thoughts

can dramatically influence the way water crystallizes.

Skeptics beware. You are free to decide that water is

merely a commodity and a receptacle, and that all water is

the same; or you can choose to view it as the great Water

Wizard as “father of implosion theory” Viktor Schauberger

did when he called water the “blood of the Earth”.

After all, the average human drinks roughly 60,000 liters of

water in a lifetime. Similarly, mature oak trees can transpire

150.000 liter of water per year!

Water is life. It is in fact what we look for on other planets

to document its presence. But a more nuanced approach

to this idea would say that water facilitates life. It is the

medium by which the energy of life, or “life force,” travels and

communicates. In the same way sound waves cannot travel in

space with no atmosphere, life waves cannot travel on Earth

without water present.

The basis of acupuncture, homeopathy, and the biodynamic

methods of farming and making compost are that subtle

energies can be utilized and imprinted into water and

“remembered,” for lack of a better word, and can actually

be manipulated and used with intention to grow healthier

people, plants, and planet.

As described by Ehrenfried Pfeiffer in the preface to The

Agriculture Course, Rudolf Steiner “called for a pail of water,

and proceeded to show us how to apportion the horn’s

contents to the water, and the correct way of stirring it…

(he) was particularly concerned with demonstrating the

energetic stirring, the forming of a funnel or crater, and the

rapid changing of direction to make a whirlpool”.

This is the basis of the biodynamic methods of stirring BD500

and BD501 for use as what are called “field sprays.” Steiner

was showing the farmers how to capture and leverage the

etheric and astral forces of plants and animals in Nature, and

using energized water as a tool of delivering them to the field.

Viktor Schauberger made many discoveries around the

regenerative nature of implosion on water. It is the implosive

moment in water where the organizational ability of water

molecules becomes vulnerable and receptive to subtle

energies. So when Steiner suggested the flow be reversed

in the bucket “to make a whirlpool”, rather than simply

“changing directions”, he was accomplishing this implosive

moment.

Intentioned growers can take advantage of this phenomenon

in their gardens by using one of the vortex-style mixing

machines on the market, or stirring fertilizer solutions

back and forth for at least 20 minutes (Steiner instructed

for an hour) in order to energize and potentize, or bring

higher order and synergy amongst the ingredients.

This is how the dynamics of a meandering river work, or

the life-giving energy experienced by surfers in the ocean

and paddlers on a river. Think about it, compared to the

efforts of dissolving oxygen with air pumps in water to grow

with hydroponics or brew compost tea, one doesn’t have

to aerate a river or the ocean, when given an opportunity,

water seeks the form of the implosive vortex in order to

regenerate and energize itself.

It is well known that water responds to celestial energies

and cycles. This sensitivity in water can be seen in the

influence of the moon on tides, or the age-old strategy of

felling trees during the new moon when the moisture and

sap are at their lowest levels. Pliny the Elder (23 – 79 AD)

advised Roman farmers to pick fruit for market before the

full moon, as it weighed more, but to pick fruit for their

own stores at the new moon, as it would last longer.

Water is so much more capable and complex than we give

it credit, so how is it that we can know so much, and at the

same time, so little about something so important?

It is not for a lack of research. Dr. Gerald Pollack of the

University of Washington describes in his book The 4th

Phase of Water the tribulations of the history of water

investigation in great detail. The Russians in the 1950s, and

the French in the 1970s, both made aggressive campaigns

to document the mysterious nature of water - but were

rebuked in the name of “science.”

The promiscuity of water makes it near impossible to

isolate pure H2O, which translates to “contamination”

in the realm of modern popular science and the scientific

method. This phenomenon of water has halted almost every

professional foray into the mysteries of water since the turn

of the twentieth century. And here we are today.

With a more direct and nuanced understanding of water, there

is enormous reservoirs of potential at our fingertips. The

capacities of water speak to the efficacy of raw food, sprouting,

and unpasteurized juicing. Water that is “structured” by living

cells is in a different, and a more invigorated state, than the

average water that we experience from the tap or bottle -

resulting in health and rejuvenation.

Not only is water structured by life more valuable, but it

turns out that we can make it easier for water to get inside

of cells as well. Peter Agre was awarded the Nobel Prize in

Chemistry in 2003 for the discovery of the aquaporins. They

are protein channels in the cell that regulate water, and they

exist in bacteria, plants, and animal cells. In the human body

alone, at least eleven different variants have been found.

The molecular structure of water determines cells’ ability to

access adequate water. Basically, what Peter Agre discovered

was that cells need to drink water one molecule at a time,

meaning, if the structure and surface tension of water is too

high we can be medically dehydrated despite the amount of

water we drink, because we are simply irrigating our kidneys,

not hydrating our cells. The same is true for plants.

In regards to the potentials of water in life and society - we

live a filtered existence. We elicit this understanding every

time we use rainwater in our gardens, invest in a water filter,

or make the decision to purchase a bottle of drinking water.

So let’s take this one more energetic step further. We must

inspire our imaginations towards water. We need more water

conservationists and connoisseurs. Pondering the importance

and mysteries of water go a long way towards levering its true

potential in our gardens and in our lives. Here’s to paying more

attention to our water, it does a body and a garden good. 3

Everybody knows the ironic tale of the thirsty old man lost at sea. This unfortunate chap, stuck in his boat,

dying of thirst, mouth as dry as dust, is surrounded in every direction by countless gallons of water but, due to

the 10,000 or so PPMs of sodium, and 19,000 PPMs of chloride inconveniently present in solution, he’s unable

to satisfy his thirst with even a single salty sip!

too often create lime-induced chlorosis. Apple, peach,

citrus, and soybean crops often suffer in this way. The

telltale sign of iron deficiency is a yellow leaf with green

veins (Hindt and Geurinot, 2012). This is because iron

is a key component of chlorophyll—nature’s very own

solar panels—so no iron means no green colour in your

leaves, and markedly reduced photosynthesis. On the

other hand, if you can give your plants enough iron, then

you’re essentially allowing them to “invest” in themselves.

Basically, you’re granting them a free license to produce

more chlorophyll, and with it, the ability to capture more

light energy.

Iron’s accessibility problems do not necessarily end

in soilless, hydroponic cultivation environments.

Furthermore, it’s all too tempting for inexperienced

growers to underestimate the importance of iron, as

well as other so-called “trace elements”. The misguided

rationale runs along the lines of—‘if plants only need, say,

between 5 and 12 parts per million of iron in solution—

can it really be that big a deal?’ Answer—yes indeed!

In experiments with tomatoes in NFT systems, large

differences in root development were observed between

plants grown in low versus high iron environments.

(Sonneveld and Voogt, 1984.) Moreover, optimal yields

Iron’s situation is quite similar. (It’s all too tempting to

claim it’s “ironic”.) For millions of years, iron deficiency

has blighted bacteria, plants, animals, and humans, and

yet, it’s the fourth most abundant element in the earth’s

crust. Take a soil sample from your backyard, and you’ll

find iron mentioned in the lab report. So why, in the midst

of all this abundance, did the World Health Organisation

recently state that iron deficiency remains the most

common nutritional disorder on the planet—and not just

in developing countries either (www.bit.ly/WHO-iron)? In

fact, over two billion people all over the world (Rodgers,

et al., 2004, Velu, et al., 2014)—nearly one in three of us—

are technically anaemic, largely due to a dearth of iron in

our diets. So what’s going on?

In order to solve our manifold iron problem, we would do

well to start with plant nutrition. Give consumable plants

enough iron, especially if they end up in the parts of the

plants we actually ingest, and it’s a happy domino effect

from there on up the food chain. However, it’s a lot easier

said than done. The key problem centres around iron’s

poor solubility in soil (Carvelho and Vasconcelos, 2013).

Iron occurs naturally as goethite and hematite—both

insoluble polymers (Ramimoghad, et al., 2014)—meaning

plants can’t benefit from them. Iron has a positive charge,

and is attracted to negatively charged clay particles in the

soil as Fe3+. (Fe2+ is attached to other molecules due to the

loss of an electron, and its unstable state.) Your plants’

root hairs continually pump out protons in the hope of

disassociating any Fe3+ oxides, languishing on the surface

of a clay particle in the soil, but it takes a whole lot of

energy (and, dare I say, luck) to snatch them up (Kim and

Guerinot, 2007., Hindt and Geurinot, 2012., Kobayashi and

Nish, 2014).

Iron plays even more hard-to-get as soil pH rises. Adding

calcium to the soil in traditional methods of liming can all

Iron EDTA Chelate

were only achievable when adequate amounts of iron

were present. Interestingly, the specific concentration

was less in rockwool culture than in NFT, perhaps due

to the increased amount of root hairs that rockwool

promotes.

Hydroponic nutrient formulations use chelated forms

of iron (most commonly EDTA and DTPA) to keep iron

in solution. A chelate is a molecule that surrounds a

metal ion and prevents it from precipitating. All sounds

like a wonderful solution to our iron problem, doesn’t

it? But, in reality, the use of chelating chemical agents

is far from ideal.

To begin to understand why; imagine a ping pong ball.

That’s your iron. Next, imagine that ping pong ball

grasped tightly by a six-fingered man. That’s your EDTA

chelate. You ask the mutant man politely for the

ping pong ball, but he’s rather attached

to it, and not letting go easily. Finally,

mainly due to your amazing skills

of negotiation (protonic energy)

you manage to persuade him to

relinquish his precious ping pong

ball. (Iron dissociation.) But—it’s

only now that you discover that

some helpful soul has deposited a

small blob of glue on the tips of each

of his six fingers. (EDTA’s six bonds with

the iron.) So, as he tries to release the ping

pong ball from one of his sticky fingers, it ends up

sticking to another. Eventually you lose patience, get

out your meat cleaver, and BASH! You relieve the man

of both his ping pong ball and his hand. (Plant absorbing

both chelate and iron.) What a palaver for just a tiny

bit of iron.

It gets worse. Chelates don’t fair

well under UV-sterilisation.

So, if you’re recirculating your

nutrient solution and treating

it with UV-C lamps, your

precious iron will fall out of

solution, and you’ll need to re-

dose before feeding it to your

plants again. To compound the

issue even more, iron is an

immobile element meaning

your plants can’t simply

translocate it from one of its

parts to another.

A solution, a revolution even, may well be on the

horizon in the form of nanotechnology. No, I’m not

about to conjure up a futuristic vision of atomic-scale

nano-bots working tirelessly to deliver iron to our

plants. Well, not exactly. Iron oxide nanoparticles

(that’s particles between 1 and 100 nanometers—a

million nanometers are equal to a single

millimetre. (Niar et al., 2010)) can be

“wrapped” in amino acids and held in

solution—allowing plants to uptake

iron via simple diffusion. No energy-

sapping, time-wasting negotiations

required.

Plant response to iron oxide

nanoparticles is dramatic, to say the

least—lush, green foliage, super fast

growth rates, shorter vegetative periods,

faster fruiting, and significant yield increases. Nano-

nutrients are set to rewrite the rulebook for both soil

and hydroponic growers—however, it is likely that only

cultivators growing very high value crops will be able to

justify their cost as the technology is barely out of the

laboratory (Khot, et al., 2012). Keep your eyes peeled

for some very interesting peer-reviewed studies in

horticultural scientific journals later this year. 3

100 years ago, and 75 years ago, the UK (and the world) faced an enemy that impacted on food supply and

food safety. We implemented rationing, and an unbreakable group strength to overcome these obstacles.

In the modern era, the UK and the world face a new set of common enemies; climate change, water stress,

energy shortages, resource limitation, social inequalities, and societal need for healthy food.

Here’s some of the questions that we’ll answer in this series,

followed by the facts, figures, and stories of the people that

these policies have affected, and continue to affect.

Q. What is the UK’s food industry worth, and

how much do we import/export?

A. The food and drink supply chain is the UK’s single largest

manufacturing sector. It accounts for 7% of GDP, employs 3.7M

people, and is worth £80Bn per year.

It exported £12Bn of food and drink in 2007. Britain is not self-

sufficient in food production; it imports 40% of the total food

consumed, and the proportion is rising.

Q. How much does the UK consume and waste

as a nation?

A. There was a rise of 4.0% in 2013 to £196 billion spent on food

and drink. We wasted 7 million tonnes of food in 2010.

Q. Food security? Who is ‘food secure’, and

how many are ‘food insecure’?

A. Food security: “The state of having reliable access to a sufficient

quantity of affordable, nutritious food”. In 2014, more than 20

million meals were provided to people unable to provide for

themselves. 1.1 million people attended food banks in 2015. This

number could be higher as the cheap ready meals that are the

staple of many in the UK would not qualify as ‘nutritious food’.

When is it time to stop calculating risk and

rewards, and just do what you know is right?

At the beginning of the year, I was chatting with Eric

(Coulombe) about our interests, and some ideas for new

articles. We were talking about food policies in different

countries, and thought an article on UK food policy would be

a good one - to see where the UK stands on social, political,

and economic food policies. So, research into the subject

began. The more I learnt about the food policies in the UK

and globally, the less I could write on the subject, or that’s

how it felt.

It was extremely disturbing to me during the research when

all the facts and figures started becoming apparent, and how

disproportionately everything is spread out - not just in the

UK, but everywhere. So, I have U-turned on writing one

article, and will split this topic into a few parts. Part I covers

the facts and figures of UK food policy in the last decade to

raise awareness of what’s happened, and is probably going

to continue to happen if we don’t take action. Next issue in

Part II, we’ll bring together the facts/figures, and try to make

sense of why the UK food policy isn’t working… There’s

more than likely going to be a ‘Part III’, but that will become

clear as more in-depth research is carried out, and more

questions need answering.

3.5 MILLION TONNES OF

EDIBLE FOOD IS WASTED A

YEAR

Q. How many people are overweight or obese,

malnourished, or living in food poverty?

A. In the UK 61.7% are overweight or obese (38,460,000), and

3 million people are malnourished. Surprisingly, people that are

overweight and obese can contribute to this 3 million people. This

shows that the quality of food available at low prices is insufficient,

or that knowledge of food, cooking, and

nutrition has severely diminished over the

last few decades.

Q. Falling food prices, in-

creased farming intensive-

ness, and a lack of sustain-

ability - where are we going

to be in 20 years?

Opinion. I am an optimist, and believe

that when these issues are raised, the

people will take action to prevent our situation from getting much

worse. These issues will be researched for Part II.

Q. Why has all this been allowed to happen,

and what can we do to reverse the trend?

A. This question will hopefully be answered in the next edition of

Garden Culture as we answer more questions, and dig deeper into

the UK food policies.

More questions will appear as we answer the questions

already asked, but that’s the nature of learning… The more

we learn, the less we know.

I want to present a couple of facts that will hopefully make

you think about the current situation in

the UK, and how that makes you feel.

Fact 1: Food prices have risen 18% in

real terms since 2007, taking us back to

the late nineties in terms of the cost of

food relative to other goods.

Fact 1.1: Median income after

housing costs fell 13% between 2002 and

2013 for the poorest 10% of households.

We have 1 in 5 people living below the poverty line.

A rise in food prices is a significant problem for the poorest

households, because they spend a greater proportion of

their income on food. Therefore, a rise in food prices has a

disproportionately large impact on money available to spend

elsewhere. This could be further education, healthier food,

a safe environment (heating, electricity, shelter), and other

amenities that improve the overall well being of the UK’s

population.

Consider a low-income household at this time

of year. Do they spend the money they have

on food, or extra heating to keep the family

warm? If they spend it on food, do you think

it’s healthy fruit and vegetables, or enough £1

frozen meals to last the week - full of sugar, fat,

and chemicals?

The BMJ (British Medical Journal) published in

2015:

“For the poorest in our society, up to 35% of disposable income

will now be needed for food, compared to less than 9% for the

wealthier. This will increase reliance on cheap, highly processed, high

fat, high sugar, high salt, and calorie dense, unhealthy foods. Re-

emerging problems of poor public health nutrition such as rickets

and malnutrition in the elderly are also causes for concern”.

(John D Middleton Vice President John R Ashton, Simon

Capewell Faculty of Public Health).

Fact 2: In 2013 the UK population was 64 million, from this

61.7% were overweight or obese (38,460,000). From 1993-

2014 the amount of overweight people went from 14.9% to

25.6%; an increase of 6.5 million people.

Fact 2.1: 500,000 individuals visited a food bank in 2015

with 1.1 million total visits.

Fact 2.2: Hospital admissions for malnutrition in England

almost doubled in the years between 2008 and 2013. (This

could be due to better screening processes.)

Fact 2.3: 7 million tonnes of food and drink (2010) is

wasted every year, with more than 3.5 million tonnes of that

being edible.

Ugly food is wasted due to its

lack of appeal in shops to the

consumer. There are mountains

of fruit and vegetables that go to

waste, because it’s not aesthetically

good enough. Policies are currently

looking at how to increase food

production, but we need to address

the distribution of food, and the

increasing food waste that would

balance the scales in favour of decreasing food poverty, and

improving societal health.

Actual food waste can be fed to pigs, but this was made illegal

due to the foot and mouth crisis. However, there is no scientific

evidence to back this up, and it needs to be researched further.

We can produce more food from our waste food, this could

be the beginning of new sustainability procedures, and further

our efforts to eradicate food poverty in the UK.

To conclude this article, and to try to emphasise the scale of

the food waste problem, ask yourselves a question;

Q. Have you ever bought a sandwich from a shop?

How many of those sandwiches had a crust?

Where do all the crusts go?

It’s not about saving the environment, it’s about creating an

environment that doesn’t need saving… 3

WE HAVE 1 IN 5 PEOPLE

LIVING BELOW THE POVERTY

LINE

A N N O T R E L L I SA no-lean, no-rot, no-rust trellis! French designer, Frédéric

Malphettes, created a configurable hanging design that

works indoors or out. He used 5mm stainless steel wire

to create over-sized octagon chain links that you add or remove

links as needed.

Blanket a wall with vines, or create individual plant ladders

hanging from the ceiling, pegs, or a frame. Made in France. Sold

through ArchiExpo.com via inquiry only:

www.bit.ly/chain-trellis.

cool finds

A I R B O N S A IBeyond cool. The thing you never

knew you must have until you’ve seen

it...floating bonsai. The brainchild of Hoshinchu in

Kyushu, Japan - the plants hover and rotate above

a pottery base. It works through repelling magnets

and balance.

Their Kickstarter page shows 6

different containers and energy

bases. They raised almost 5 times

their goal in just 6 days. Not a

bonsai expert? Watch the How

To Plant video... and grow

something seasonal. Very zen!

Check it all out:

www.bit.ly/air-bonsai..3

EDYNFinally! A way to

make growing

easier. This cool garden

gadget addresses gardening

challenges - anywhere.

It’s the first connected

outdoor garden monitor that measures soil

moisture, humidity, fertility, light, and temperature

with real time reporting, alerts, and can control

irrigation by dryness.

A Kickstarter project that not only turned into

a reality, but Home Depot USA stocked it fast.

The campaign was wildly successful within days of

launch. Looks to be out of the early adopter stage

now. Check it out: www.Edyn.com.

F LOAT I NG WALL GARD ENAs unique as Nature! The SEED planter

project is the work of internationally

exhibited designer, Taeg Nishimoto, a University of

Texas architecture professor.

Nishimoto used crumpled Tyvek to texture

concrete poured into profiles formed from river

stones. The 5/16” (8mm) thick tiles appear to float

on the wall, because the plant pot is attached to

the back of it. In his exhibit, 2” pots (4.5cm) were

used to keep them as close to the wall as possible.

More images: www.bit.ly/tn-SEED.

1

2

3

4

5

GARDENCULTUREMAGAZINE.COM 37

M U S H R O O M L I G H T SJapanese artist, Yukio Takano, makes great use of local natural waste

fashioning battery-powered LED mushroom lamps. The wiring and power

source are hidden in on the bottom.

Enchanted? Many are, yet unfortunately, Takano

lamps can only be had in Tokyo. But you can

make one! DIY’ers on Instructables.com have

easily duplicated the look substituting translucent

polymer clays for Yukio’s glass caps.

Get Inspired: www.bit.ly/takano-gallery.

How To: www.bit.ly/shroom-lamps.

GREEN PRODUCTS I GARDEN CULTURE

All the world loves bananas, indeed, it’s the 4th

most valuable crop globally. Only rice, wheat, and

milk trump bananas in trade. Yet, this fruit that

shaped the world is a problem. Not the banana

itself, but how and why an exotic fruit from the

tropics became, and remains an inexpensive, sea-

sonless staple food worldwide.

Being picked green, and gas-ripened after trans-

port sound bad? If only that was the truly unde-

sirable part.

B A N A N A S A R E C H E A P F O R A R E A S O N , A N D

R E P R E S E N T F A R - R E A C H I N G

E N V I R O N M E N T A L , S O C I A L ,

E C O N O M I C , A N D P O L I T I C A L

I S S U E S . ”

THE BANANA KINGSThe first tropical fruit to arrive in the North, bananas were

a costly luxury, but quickly became cheap food for common

folks. Normally, this happens only when an abundant crop can

be grown locally with few inputs, including labor. But bananas

are quite the opposite. A banana farm is a demanding thing in

terms of landmass, growing inputs, and labor - yet, it’s always

been one of the biggest profit-makers.

Bananas are cheap for a reason, and represent far-reaching en-

vironmental, social, economic, and political issues. The banana

trade is, and has always been, rife with

subterfuge, injustices, and economic

imperialism. An in-depth accounting of

how this became a global staple crop

has all the elements of a blockbuster

film: violence, sex, drugs, greed, politics,

corruption, war, and more.

Ever heard of United Fruit? How about Standard Fruit? Sure,

you have. The first company, now Chiquita, created the model

for today’s globalized agriculture industry, and once command-

ed 80% of the banana export trade, though the original com-

pany didn’t adapt to changing world conditions. The second

early banana trader is now Dole.

In the 1980s, 80% of the world banana trade were held by:

Chiquita, Dole, Del Monte, Fyffes, and Noboa. The first three

are long established US-based corporations, while the others

are relatively new to the game. Today these companies domi-

nate only 39% due to operational repositioning.

Until just recently, your bananas came from the side of the

world you lived on. Less travel ensured the import prices re-

mained low, but now prices plummet - regardless of harvest

origin.

A MONO MESSThere are two types of banana growers; smallholders and the

banana kings. The first use far less chemicals, require less land,

and lack clout on the market. The second, transnational cor-

porations, bring the perfect banana to market through mo-

nopoly, monoculture, and mega monocropping made possible

only through using hundreds of agrochemicals, massive defor-

estation, environmental destruction, and social and economic

control.

Additionally, the plants are all clones. It’s a rare seedless mu-

tant reproducible only by division or tissue culture, which makes

planting the crop much costlier than seed. They are all identical,

having no diversity, no immunity to pests or disease, and trans-

planted divisions increases the risk of devastating infection. It’s a

highly unsustainable crop threatened with extinction.

Until the 1950s all imported dessert bananas were Gros

Michel. Then a Fusarium species fungus called Panama Disease

wiped them all out, which cannot be eradicated from the soil

once present. All growers were forced to switch to the lesser

Cavendish banana. Now a second fungal disease, Black Siga-

toka, has reached epidemic levels globally - and a more virulent

strain of Panama Disease that spreads like the plague threatens

plantations everywhere.

Between eradicating weeds, fighting

pests and disease, and maintaining soil

fertility for the demanding feeders that

banana plants are - over 400 agrochem-

icals are used. Only cotton uses more.

Some chemicals used on bananas are

outlawed in Europe and North Amer-

ica.

Interestingly enough, the FDA reports that there are only 4

pesticides found in bananas, some suggest that the inedible

peel isn’t tested. Either way, 39-57 pounds per acre applied an-

nually is excessive! The environment, and the health of banana

workers are suffering.

HEALTH & ENVIRONMENTPests and weeds are developing chemical immunity. Increasing-

ly stronger pesticides, and in greater quantities, are being used.

On numerous plantations the chemical spend greatly exceed

their labor costs. These massive growing operations are the

result of millions of acres of deforestation, which causes soil

erosion and increased flooding. The deluge of fertilizers and

pesticides sinks into the soil, and runs off into the waterways,

eventually spilling into the ocean.

The contaminated water is killing the fish, and polluting local

water supplies, causing negative impact on the health of work-

ers and communities around plantations. An estimated 85% of

aerially applied pesticides never hit the plants, drifting over the

whole area... 22-56 times a year.

“Health impacts of extensive agrochemical use are numerous, rang-

ing from depression and respiratory problems to cancer, miscarriag-

es and birth defects. Tens of thousands of workers left sterile by the

use of a nematicide, DBCP...” --

BananaLink.org

A H I G H L Y U N S U S T A I N A B L E

C R O P T H R E A T E N E D

W I T H E X T I N C T I O N

A N E N T I R E C O U N T R Y ’ S

E C O N O M Y C A N B E D E S T R O Y E D

I N S T A N T L Y W I T H O U T T H I S

E X P O R T

SOCIAL & ECONOMICCurrently, exporters have no control

over the wholesale cost of the fruit.

Now it’s the grocers who determine

where your bananas come from by

price. This race to the bottom re-

moved country of origin preferences.

The cheapest source wins, further re-

ducing incomes for smallholders and workers.

Workers’ pay for 60-72 hours a week laboring in stifling cli-

mates over 9-12 months is based on the price their product

sells for. This week, bananas are 53 cents a pound in my neigh-

borhood, and the people who made their export possible re-

ceived 10% of that, or less. And this is for the portion of the

yield that is perfect; 30-40% of the harvest is an environmen-

tally toxic farm waste, and any less than perfect fruits arriving

for export sell locally for much less.

Even before supermarket chains had the power to deter-

mine the price of bananas, field workers and small producers

weren’t making much money. Many already existed in poverty,

unable to pay for basic living needs - and now they make less,

even though their cost of living has skyrocketed. Positive social

development in banana export countries is impossible. Cheap

bananas have taken many lives, and only reinforce conditions

that have prevailed in this industry since its birth - exploiting

people, and violating human rights.

THE SOLUTION?Avoiding bananas might come to mind, but this won’t help the

millions of people living in the fragile economies created by

monoculture bananas. Nor would the loss of their industry to

destruction by disease, which will take place, it’s only a mat-

ter of time. Chemicals are only making pathogens and pests

stronger.

An entire country’s economy can be destroyed instantly with-

out this export, the population of which is already living in

poverty. This race to the bottom pricing driven by big stores

like Walmart and Aldi’s is taking even that meager bit of se-

curity away. These transnational retailers are no better than

the banana kings. They haven’t started a war, or overthrown

a government... yet, but they’re masters at exploiting humans

for profit.

After a century of availability, banan-

as are an important part of nutritious

food diversity that is ingrained in all

cultures’ diets. It’s not like we have

no options going forward - there are

other sweet, edible banana varieties.

The fruits may not be so big, they

may not be yellow, and the flavor is different. The banana em-

pires have simply chosen the largest, prettiest, and heaviest

bearing variety for their factory farms.

Banana workers need better working conditions, and inde-

pendent trade unions to educate them what that is. Huge

monoculture plantations need to be replaced with sustainable

growing models that stop environmental devastation, and re-

build the soil. Smallholders have a far better model. Diversity

of crops, even of banana varieties themselves is needed. And

this horrible misuse of many for the benefit of a few, along with

disproportionate economic and political power that rides on

top of it all needs to be abolished.

How we get there is the cause of much debate. Introducing

more sustainable dessert bananas to replace the Cavendish

variety is long overdue. Many unknown-to-the-global-market

varieties have better flavor, but Chiquita has been working

on developing one for commercial production through hand-

breeding. Known as GCTCV 219, it’s both sweeter and better

tasting, and testing of it started in Australia and Asia in 2014.

Don’t boycott all bananas. There are organic and fairtrade

brands available, both of which do a lot in terms of alleviating

the wrongs that traditional banana growers have brought to

the land, the forests, their workers, and the local population.

Yes, they cost a bit more, but

fair trade bananas pay workers

higher wages, and give them

safer places to work under

better working conditions.

Covering a topic this vast in

so few words is impossible.

I’ve barely scratched the sur-

face. 3

DIG DEEPER:· www.bit.ly/science-quarterly

· www.bit.ly/bananas-shaped-world

· www.bit.ly/Banana-Link

· www.bit.ly/rfa-bananas

· www.bit.ly/fairtrade-bananas

· www.bit.ly/banana-chain

· www.bit.ly/ethical-consumer

· www.bit.ly/tropical-race-4

large fields. Clover can also be used as a companion for

taller plants, both for weed control while living, and as a

nutrient source as they complete their life cycle.

Since clover makes its own nitrogen, it can be planted

in areas with poor or overworked soil such as lawns to

help improve them. It can be used either as an addition to

existing grass lawns, or as a replacement for them. Once

established, clover is more drought tolerant than grass,

needs less fertilization (generally none), is aggressive

enough to push out most weeds, and even comes in dwarf

varieties to minimize the need for mowing. It is also a

favorite of honeybees, who could use all the help they can

get these days, and is even resistant to pet urine browning.

When the clover plant dies, it can be left in place to

decompose and enrich the soil, or be harvested and

composted to feed to other plants. This aspect of clover is

why it is known as one of the “green manure” plants, and

why it is a common plant to include in crop rotations. The

clover grown one season can be turned under or mowed

down to help feed whatever plant is grown next in the

rotation.

If for some reason a garden area won’t be used for a

season, consider sprinkling some clover seeds. Mix the tiny

seeds with sand to help with even coverage, and give them

enough attention to get them started well. Crop rotation

techniques can be used in small garden plots just as well as

Clover is a useful legume that is related to peas and beans. It also has pretty, if somewhat plain,

flowers when allowed to bloom.

One of the most useful aspects of clover is its ability to pull nitrogen out of the air. As with

other legumes, it can form a symbiotic relationship with host specific nitrogen fixing bacteria

called rhizobia. In the case of clover, the specific bacteria is Phyllobacterium trifolii. Commercial

clover seeds are often inoculated before sale to ensure the presence of the bacteria. A clover

plant that has rhizobia bacteria will form root nodules. The root nodules have value, because

there the bacteria can fix nitrogen directly out of the atmosphere, which it supplies to the plant.

When used as a lawn, there are a few drawbacks. First of

all, it is not as resistant to foot traffic as grass, which is a

legitimate concern for those folks that have family rugby

matches out on the front lawn, if it is to be used as a

playing field, grass is probably a better choice. For the rest

of us, just put some paving stones along whatever path

gets worn from entering and exiting the house, and enjoy

not needing to push around a lawn mower as often.

The second drawback has led to an unfair smear campaign

against the noble clover mounted by the broadleaf

herbicide people. Namely, that it can be killed with

broadleaf herbicide weed killer. These companies even

regularly advertise the effectiveness of their products

against clover, as if to suggest it is something undesirable

that should be killed. In other words; they make a product

that kills off a drought tolerant, self-fertilizing, low

maintenance lawn, in preference for water hogging, soil

depleting grass that needs mowing every week or two, and

are proud enough of that to advertise the fact.

The solution to the second drawback is simple, don’t spray

your lawn with broadleaf herbicides.

The third is a fair point, and it is that for best appearance,

clover lawns should be reseeded more often than grass

lawns. A partial solution to this is to allow the clover to

flower, set seed, and supplement with additional seedings

as needed. While this does incur both cost and labor, there

is the savings from not buying fertilizer, mowing as often, or

watering as often to consider.

Clover is one of the plants I recommend serious gardeners

to familiarize themselves with, it touches on a lot of

important concepts, including the sustainable fertilization

of crops. 3

If you are a small or a medium indoor gardener

thinking about scaling up, and building a commer-

cial greenhouse... beware, a lack of knowledge has

been revealed. From industry investors to famed

consultants, very few have built a greenhouse, let

alone an eff icient structure with specif ic technol-

ogy f ine-tuned for a specif ic crop. There is a mul-

titude of options for greenhouse manufacturers,

and most are f ighting for their place in line to

dominate new sectors in horticulture.

With the overload of choices, charismatic salesman, and

the size of this investment - you should not rely on personal

knowledge of other industries. Building a greenhouse is very

specific. The best approach is to hire a consultant that knows

greenhouses. Knowing how to operate a greenhouse does

not qualify one to design the structure or systems. For this,

you need to have built greenhouses, as well as remodeled

them in a multitude of situations.

The best analogy I have come up with for building a well-

designed greenhouse is the similarity to climbing Mt. Everest.

Even experienced climbers hire the Sherpa to lead the way,

and help bear the load - just as your greenhouse consultant

should do. It is an immense task to complete from design,

licensing, and permitting to selecting equipment, and planning

the budget with a reliable timeline.

Don’t slack on your Sherpa selection! They should have a

track record of success, and be able to provide other happy

customers as references. The consultant, when asked, should

be able to tell you of a time or two where they’ve failed, and

explain what was learned. None of us are perfect, and if you

haven’t messed something up along the way... you haven’t done

it very long. Finally, check the credentials. While a degree and

work history aren’t everything, they certainly provide a solid

foundation. The cost of a consultant may be expensive, but

like a Sherpa, they will save you money, or even your life. And

don’t be alarmed when they ask to be paid in advance (just in

case you fall off the mountain along the way).

When selecting a greenhouse manufacturer, the consultant

should be involved every step of the way. I have worked with

many different greenhouse manufacturers, and not once

have they designed a facility the way I wanted it the first time

necessary. Yes, a sealed greenhouse with

a low amount of outside air exchange may

get very hot, but with properly designed

and installed cooling systems, and energy

curtains - we can accomplish amazing

things. The opposite is a cool, dry natural

environment that will easily be duplicated in an open air flow

greenhouse simply by creating air exchange. In any open air

scenario, air filtration should be used to prevent insects, such

as thrips.

Finally, if you are well-funded, and aspire to be a true

pharmaceutical production facility, there are food safe, and

without input. There are so many factors

that go into the design. At the top of the

list is preventing problems, not fixing

them after they arise.

The next consideration is the local

environment: wind, heat, snow, hail, humidity, and light

levels. Every single location is different, and the structure

should reflect that.

The other obvious consideration is the crop itself. Some

plants prefer it to be hot and humid, this means in a high

humidity environment where a sealed greenhouse may be

SCALABILITY IS THE KEY TO LONG TERM

SUCCESS

aseptic greenhouses available. The

options for these extremely high tech

systems run into the millions of dollars.

Once you are to the point of selecting

the greenhouse manufacturer, there

is a high likelihood you have at least a

small team of people working on the

process. The greenhouse manufacturer

should be an addition to the team, not

the coach. Being a team player is often

difficult for greenhouse manufacturers, because they have

their way of doing things. They like to build what they always

have, and fear change. While someone has to develop the

greenhouse layout, it is a team decision. At the end of the day,

the greenhouse manufacturer will build it how it is requested.

Planting density is probably the most subjective piece of the

design puzzle, and every grower will have different sizes desired

for plant stages, which creates complexity of the design. The

main key of the layout for a facility like this is what I call a

‘single direction flow through’ design. Basically, that means

a first in, first out protocol, but if the processes themselves

aren’t incorporated into your design, once the greenhouse is in

production mode, employees will continually be bumping into

each other - creating traffic jams, lowered productivity, and

potential for increased contamination.

Scalability is the key to long term success. Most commercial

greenhouses that stay in business for decades have expanded,

and the most efficient designs are the easiest to scale. Literally

to the point of taking down one sidewall, and adding trusses

connected to new piers expands the greenhouse in one

direction, and with limited disruption to production.

Scalable automation creates precision in a greenhouse. It not

only removes a majority of the user error, but also creates

uniformity among the crops. The degree of the precision

created varies widely based on the equipment selected. For

example, some systems I use can have a plus or minus five

degrees variation in temperature,

where more expensive integrated

systems may have a plus or minus half

of a degree in fluctuation.

The installation and build of the actual

greenhouse is a feat, in and of itself.

Something always goes wrong. This is

where any design problems become

reality, and have to be fixed quickly,

and without slowing down the overall

build in order to minimize additional expense. Very often local

contractors will be used, but they will have supervision crews

directly from the greenhouse manufacturer. This is standard

practice, as the build itself isn’t rocket science - the hard part

is in the design.

A greenhouse manufacturer’s track record is very often their

selling strategy, but this track record can be deceiving. First

off, just because you have built more facilities than anyone

else, doesn’t mean any of them were built properly, and

building in one environment doesn’t make you able to build

in opposite ones. Asking to talk with previous customers, or

finding existing operators in other locations with the same

greenhouse is a major step toward finding the right builder.

In the end, you want a builder who will provide true ongoing

support, not just land a sale and walk away.

In closing, a greenhouse can cost anywhere between £374 and

£1872 per meter square, but how it is designed is easily the

difference between success and self-destruction. A builder will

always try to sell you a bigger structure than you ask for. Yes, it

is good for his commissions, but there is an economies of scale

factor. Most structures decrease in cost per square meter

once the half-acre, or one-acre size is achieved. No matter

what your budget is - always tell the builder it is less. This

will help anticipate the extra costs that are associated with

every project, much like buying a house. Finally, have a Sherpa

(consultant) that you trust with the life of your business,

because in the end, he or she is your guide to glory! 3

HOW A GREENHOUSE IS DESIGNED IS EASILY THE DIFFERENCE

BETWEEN SUCCESS AND SELF-

DESTRUCTION

2) Inversadale, Ross-shire

Population 1000

It’s not safe to assume that people beyond big cities have

space for growing food. Surprisingly, even people in tiny

remote villages need allotments. Such is the case in the

Scotland Highlands, where the gift of community garden

space changed the lives of the residents in this crofting

community a few kilometers beyond Poolewe. Even country

folk want a better food source, control over how it’s grown,

and environmentally friendly production.

Originally, the donated land was divided into plots for locals

to grow their own produce, but the group has evolved. Their

efforts have grown into something bigger. Thanks to a grant,

Good For Ewe acquired some poly tunnels, making year

around crops possible. They built a rainwater collection tank

for irrigation, and soon altered their production plan inside

and out to dedicate space for market growing.

60 members strong and growing like a weed.

Learn more: goodforewe.org

1) Kennington, South London

Urban GreeningThe Keeper’s Lodge at Kennington Park is buzzing

with green activity. It’s the home of Bee Urban, a social

enterprise doing all kinds of positive things with a focus

they call “honeybee-centric.” It all started 8 years ago

when London beekeeper Barnaby Shaw moved in with

four hives, and some big ideas. He’s an experienced

apiarist, having helped his father with his beekeeping

operation as a boy, and eventually taking over.

If you’re going to keep bees, you need bee food, so

they’ve transformed the outside space to provide year

around forage with fruit trees, flowers, and vegetable

gardens. The volunteer-powered organisation’s training

center, known as the Bee Barn, was built with recycled

materials. Today, Bee Urban maintains over 30 hives in 7

locations, and promotes environmental practices through

education, like urban beekeeping, solar and bio digester

energy, building bicycles from recycled parts, and more.

Process more valuable than the outcome.

Learn more: beeurban.org.uk

3) Penallt, Monmouthshire

Small Ain’t Useless

The idea that a 117 acre farm is too small to be useful or

profitable made TV presenter Kate Humble angry - so angry,

she set out to save a council farm near Monmouth from

being split and developed. Mission accomplished, it became

the site of the UK’s first closed-loop aquaponics system.

Conventional agriculture is definitely wrong, because Upper

Meend Farm is very useful, and profitable today.

Besides the passive solar greenhouse containing the

sustainable aquaponics project, there’s a lot going on

here. It’s a working farm breeding sheep and cattle, doing

permaculture, has a new orchard, a cafe, farm stays, and

courses on rural skills, smallholding, and food. Through Kate’s

company people learn they don’t need tons of land to be

more self-sustainable. The farm also boosts local economy

supporting other businesses.

A very interesting place!

Learn more: humblebynature.com

4) Wester Hailes, Edinburgh

Rethinking GreenspaceCouncil estate greenspace lawns are great for providing

a spot for recreation, but they’re rethinking its purpose

in this southwest Edinburgh neighborhood. Recently, the

Edible Estates initiative established community gardens

for residents with allotments, food hubs, and play spaces

for children. It’s a collaborative effort between the Health

Agency, the city, and urban design agency, Re:Solution, to

increase the wellbeing of the community, and decrease

maintenance costs.

The estate dwellers in Wester Hailes have really

embraced this. The plots are full, growers are socially

active, pitching in to help one another. It’s been such a

huge success that Edible Estates is exploring opportunities

to extend the program. They’re encouraging residents

to set up bird boxes and wildflower plantings, and

looking into providing training and jobs in intensive food

production.

Awesome! Inspired by London’s Poppy Estate video on

YouTube. Learn more: whee.org.uk 3

it is presented in documentary format. We are easily fooled

by presentation if we do not master the art of the science.

YouTube offers a great platform for anecdotal evidence.

There are all too many examples of it, and while some can

easily be recognized, others seem quite legit. They are well

produced, show high quality images and graphs, and the

presenter looks quite knowledgeable. It’s on video, the

pictures are convincing, you can see it with your own eyes,

right?

The amount of videos available on YouTube is overwhelming:

for any standpoint or belief - you can find “proof” in a video.

Some productions look extremely professional, adding to

the “reliability factor”. Specifically, grow trials have always

been popular: different methods of cultivation (for example,

different light sources) are compared, and of course, there

is always a clear winner. However, if you look at those trials

critically you can always see a few flaws. Let me take light as

an example, as this is my expertise.

With the rising of LED technology, you see a lot of

comparisons against traditional HID sources. Now, both

HPS and LED professional growers usually report a high

yield, but in comparisons you see that one lacks substantially,

even worse than you would normally expect to get as a result

from that particular technology. There are many reasons

why some of these results can be so different from what

you see in real life, and many originate from the fact that the

In this column Theo Tekstra discusses observations in the indoor garden culture. There is sometimes so much

urban legend, and so little science in this industry. It is time to “myth bust”, and have a fresh breeze move through

the industry.

Before there was YouTube, we had pure anecdotal

evidence, and it was the source of many urban legends.

Anecdotal evidence is defined by Webster as “based

on, or consisting of reports or observations of usually

unscientific observers.” Other sources define it as “based

on personal observation, case study reports, or random

investigations rather than systematic scientific evaluation.”

There is nothing wrong with sharing experiences you will

say, and indeed there isn’t. But to value this experience as

a universal truth can be really dangerous.

All definitions have this in common: it is usually not

based on scientific methods, or presented by scientific

observers. You need to ask yourself two things when

reading or viewing “evidence”:

1. Is the method used to obtain this result in any way

scientific?

2. Is the observer in any way a scientist?

We all know that the earth is not flat. So when someone

claims it is, because he sees no curvature, it is easy to identify

that as an incorrect claim. That is not so easy though, when

it concerns matters that we know little about. When we

seek information it is easy to be convinced by anecdotal

evidence, especially if it is presented by someone we

regard as reliable (whether that is true or not), or when

the presentation of the evidence looks professional. For

example, when supported by graphs and figures, or when

grower did not base the trial on scientific methods - or

used an incorrect application of the technology. Let me

give you a few examples:

• If the yield of one of the technologies is much lower

than you would normally expect, there is a flaw in the

application or test method somewhere. Guaranteed.

• LED, by and large, has a much more compact footprint

due to the fact that it is much more directional,

while HPS lighting mostly relies on overlapping fields

to create a uniform lighting and more horizontal

penetration of a crop. In small trials, or small square

shaped trial rooms, this of course gives the LED an

advantage, as the HPS fixture will spill lots of light on

the walls. In a large room this effect is much smaller.

Using more, smaller HPS sources will usually give

much better results in a small square room.

• At lower intensities the efficiency of the light is much

higher. There is not a linear relation between light

intensity and photosynthesis, as with high intensities

the photosynthetic rate levels off, coming close to

the saturation point of the plant. However, at high

intensity the yield per square meter will be higher,

which can be very worthwhile, and a great investment

when growing a high value crop. If you compare yield

per Watt, a low light intensity grow will always win

over a high intensity grow.

• Scientific grow trials are always done under standard

conditions. So external influences are eliminated as

much as possible. When determining the efficiency of

a light source you grow under similar intensity (PPFD),

in an as uniform as possible field of plants and uniform

lighting, and take the center of your field as the trial

sample. Trials are usually small scale, so size and room

factors need to be eliminated. I have seen trials done

in the same room where the different sources even

overlap with one another, making it impossible to get

a reliable result.

• Specifically comparing HPS and LED creates a problem

when you give both crops the same nutrient levels.

LED-grown plants, as they get much less irradiant heat,

transpire a lot less. Generally, this means that you have

to up the EC of your nutrient solution substantially.

• The climate in both rooms will differ, and this creates an

offset. Growing under LED and HPS in the same room

can actually be an advantage to the LED-grown crop, as

much stray light, and specifically - heat, is added to the

room, boosting the photosynthetic efficiency.

I am not saying that all of these trials are fraudulent, or

meant to deceive you. Not at all. There is a serious quest

in this industry to research what are the most efficient

and highest quality cultivation methods, and that is a good

thing. However, we do not see the same huge differences in

efficiency in the many real scientific trials that are executed

worldwide. LED light of the same intensity as HPS, for

example, is not 30-60% more efficient as some of these

trials want you to believe. In fact, there is much scientific

evidence that shows that there is not a big difference in yield

between the different light sources at the same intensity at

all. However, with LED light you are able to distribute the

light over a much more compact surface with much less wall

losses, which is a definite advantage in a small room, or on

a defined surface.

The moral of the story? You can not just pick and choose

your evidence. There is a reason why scientific trials are

scientific. 3

54

BY JEFF EDWARDS

55

HYDROPONICS I GARDEN CULTURE

progress came in fits and starts, with major discoveries followed by extended periods of

seeming disinterest

GARDENCULTUREMAGAZINE.COM

Jan Baptist van Helmont

Many written histories of hydroponic plant cultivation

methods mention the ancient Hanging Gardens of Babylon,

the first written record of which dates to about 290 BC.

Penned by Berossus, a Babylonian writer, priest, and

astronomer, we only know of Berossus’ writings through

quotes by later authors. Five primary authors, including

Berossus, are responsible for what we know of the Hanging

Gardens today. Their accountings were all written at a later

time, based on now lost, previously written accountings by

others.

Modern research questions whether the gardens were in

Babylon at all, yet the premise that the gardens would in

some way qualify as “hydroponic” is doubtful, based on

observations by these early writers. Diodorus Siculus,

writing between 60 and 30 BC, referenced the 4th century

BC texts, Ctesias of Cnidus, for his description of the

gardens. After detailing their construction, he includes

the following passage, “...on all this again earth had been

piled to a depth sufficient for the roots of the largest trees;

and the ground, when leveled off, was thickly planted with

trees of every kind...”

Quintus Curtius Rufus, writing in the 1st century AD,

references writings of Cleitarchus, a 4th-century BC

historian for Alexander the Great, who also described the

“...deep layer of earth placed upon it and water used for

irrigating it.” Philo of Byzantium, the author who identifies

what we accept today as the Seven Wonders of the Ancient

World, writing sometime around the 4th or 5th centuries

AD, mentions that “...much deep soil is piled on, and then

broad-leaved and especially garden trees of many varieties

are planted.”

Based on these accounts alone, it seems doubtful that the

Hanging Gardens of Babylon could in any way be considered

soilless. In all fairness, the irrigation systems required to

bring water to plantings of the reported scale, described

in the form of aqueducts and water lifts, are similar in

concept to irrigation methods employed today in modern

hydroponic systems.

Another oft mentioned comparison to modern hydroponics

in the Old World are the “floating gardens” built by the

Aztecs in the 14th century AD. Arriving in the Valley of

Mexico, the Aztec people found a landlocked swamp with

five large lakes surrounded by volcanic mountains. For some

reason, they chose to settle in swampland surrounding Lake

Texcoco, and decided to build their capital city on a small

island in the lake. Lacking any extra land for growth, the

people started building what were essentially rectangular

islands, constructed of soil, compost, and sludge from the

lake bed.

Contrary to popular belief, these islands, or “chinampas”,

didn’t float at all, but were rather attached to the lakebed

using willow tree cuttings and a variety of materials

including stones, poles, reeds, vines, and rope. Chinampas

were incredibly fertile and irrigation was unnecessary since

water wicked up from the lake. As many as 7 crops could

be harvested in a single year due to the unique methods

of composting and mulching developed by the Aztec

farmers of the time. However, based on their method

of construction it’s clear that the Aztec chinampas, like

the Hanging Gardens of Babylon, cannot be classified as

hydroponic either.

Some of the earliest recorded research into the actual

reasoning behind the growth of plants, published

posthumously in 1648, was written by a Flemish chemist

known as Jan Baptist van Helmont (1579-1644). In fact,

authorities detained van Helmont in 1634 during the

Spanish Inquisition for the “crime” of studying plants

and other sciences, and sentenced him

to two years in prison. And while van

Helmont was primarily known as the

first to articulate that there are gaseous

substances that differ from ordinary

air, as well as introducing the word

“gas” into the scientific lexicon,

he is also known for a single

Hydroponics, now commonly defined as the soilless growth of plants, has its root foundations in simple observa-

tions by early progressive thinkers and tinkerers. Like many scientific discoveries and their evolution to commercial

application, progress came in fits and starts, with major discoveries and realizations followed by extended periods

of seeming disinterest.

experiment he conducted

using a willow tree to

determine from where

plants derive their mass.

This research is commonly

known as “the 5-year tree

experiment”…

“But I have learned by this handicraft-operation that all

Vegetables do immediately, and materially proceed out of the

Element of water onely. For I took an Earthen vessel, in which

I put 200 pounds of Earth that had been dried in a Furnace,

which I moystened with Rainwater, and I implanted therein the

Trunk or Stem of a Willow Tree, weighing five pounds; and at

length, five years being finished, the Tree sprung from thence,

did weigh 169 pounds, and about three ounces: But I moystened

the Earthen Vessel with Rain-water, or distilled water (alwayes

when there was need) and it was large, and implanted into the

Earth, and least the dust that flew about should be co-mingled

with the Earth, I covered the lip or mouth of the Vessel with an

Iron-Plate covered with Tin, and easily passable with many holes.

I computed not the weight of the leaves that fell off in the four

Autumnes. At length, I again dried the Earth of the Vessell, and

there were found the same two hundred pounds, wanting about

two ounces. Therefore 164 pounds of Wood, Barks, and Roots,

arose out of water onely.”

Historians have deduced that the experiment was likely

not an original idea, rather one motivated by Nicolaus of

Cusa’s 1450 description in De Staticus Experimentis of a

similar experiment that was apparently never conducted.

Further research puts the concept of the experiment

back to a Greek work somewhere between 200 and 400

A.D. And while his research method is completely lacking

in scientific validity, it was van Helmont’s line of inquiry

and experimentation that would ultimately lead to the

understanding of photosynthesis.

In 1699, John Woodward (1665-1728),

an English naturalist, antiquarian, and

geologist challenged Helmont’s theoretical

deductions by publishing the results

of “water culture” experiments he

conducted using spearmint grown in

differing sources of water. His experiments

showed that the spearmint grew better

in water to which he added very small

amounts of soil, versus “plain” water, and

distilled water. His research also led him to

the differing conclusion

that more than water was

necessary for plant growth,

and that soil was at least

partly responsible for the

increase in the mass

and weight of plants,

indicating that he too failed to clearly grasp the

fundamental concepts of plant nutrition.

Unfortunately, progress in these areas of research

remained stagnant until the first proper water

culture experiments undertaken by a French

agricultural scientist and chemist, Jean-

Baptiste Boussingault (1801-1887), around

1840. Boussingault had established the

very first agricultural experiment station

near Alsace, France four years earlier, and

was responsible for a plethora of discoveries

related to soil chemistry and plant nutrition. Many of his

experiments involved raising plants in various soil substitutes,

1699: John Woodward conducted

experiments growing in differing sources

of water

John Woodward

including sand, ground quartz, and charcoal,

which he irrigated with solutions of mineral

nutrients.

Also in 1840, Boussingault’s fan and

contemporary, German chemist Justus

Freiherr von Liebig (1803-1873), published

Die organische Chemie in ihrer Anwendung

auf Agricultur und Physiologie (Organic Chemistry in its

Application to Agriculture and Physiology), which proffered the

then ridiculous proposition that chemistry could drastically

increase yields, and cut the costs associated with growing

food. As a boy, Liebig had lived through “the year without

a summer”, a volcanic winter event that occurred in the

northern Hemisphere after the massive 1815 eruption

of Mount Tambora in what is now known as Indonesia.

Near total crop losses that season led to widespread food

shortages, causing a global famine, and much of Liebig’s

later work towards increasing world food production was

reportedly shaped by this unsettling experience.

Liebig made significant scientific contributions to

agricultural chemistry, and was the first to put forth a

theory on mineral nutrients, identifying as essential to

plant growth the now familiar elements including nitrogen

(N), phosphorus (P), and potassium (K). Interestingly,

Liebig’s major downfall was his lack of experience in the

practical applications of his research. One of his best

known achievements was developing nitrogen-based

fertilizer, arguing in the 1840’s that it was necessary to

grow the best possible crops. However, he later convinced

himself that there was plenty of nitrogen supplied to plants

through ammonia contained in precipitation, and strongly

argued against using nitrogen in fertilizers in his later years.

Despite his wavering, he is commonly known as the “father

of the fertilizer industry” - not only for his identification of

nitrogen and other elements as being necessary for plant

growth, but also for his development of the Law of the

Minimum, which observed how individual

nutrient components affected crop

growth.

In 1860, Ferdinand Gustav

Julius von Sachs (1832-1897),

a German botanist and author

of Geschichte der Botanik

(History of Botany) (1875),

a highly regarded historical

chronicle of the various branches of botanical science

from the mid-1500’s through 1860, published his nutrient

solution formula for “water-culture”, and revived the use of

this technique as the standard tool when researching plant

nutritional needs. His plant nutrient formula, with only

minor changes, was almost universally used for

the next 8 decades.

Sachs’ experiments blazed the trail,

and in rapid succession, other

scientists followed up his work - the

most notable of which was Johann

August Ludwig Wilhelm Knop

(1817-1891), a German agricultural

chemist. While Sachs’ interest

lies primarily with studying plant

processes while establishing botanical

knowledge, Knop can rightfully be

called the true father of water culture, as his

experiments laid the foundation for what we now know

today as hydroponics.

In his early experiments, Knop sprouted seeds in sand and

fiber netting before transplanting the seedlings into cork

stoppers with drilled holes, securing them with cotton

wadding, and then suspending them in glass containers filled

with solution. By doing so, Knop inadvertently established

the technique most widely used for future laboratory

experiments.

johann august knop

Julius von sachs

Justus von Liebig

johann august knop

Using this method, Knop was the first to realize that plants

gain a large amount of weight simply from the food stored

in their seeds, and that seeds provide nourishment to the

parts of the plant that form first. By this time it had also

been established that soil nutrients must be in a soluble

form for plants, and that the amount of soluble nutrients in

soil was miniscule compared to those that were insoluble.

These two pieces of information would form the basis for

Knop’s future scientific experimentation.

What wasn’t available then were specific ways to measure

these properties, such as osmotic pressure, nor did

researchers of the day have any idea of what those

properties might be. And while Knop deduced that nutrient

solutions that were too concentrated might do more harm

than good, he had no idea why.

Despite this lack of understanding, in 1860, Knop

successfully grew plants, without soil, weighing many times

more than their seeds and containing a larger quantity of

nutrients. In 1868, other scientists using Knop’s methods,

grew buckwheat weighing 4,786 times more than its

original seed, and oats weighing 2,359 times more. These

experiments firmly established the fact that plants can

indeed be grown successfully, and productively without

soil.

Over the next few decades, little effort towards developing

commercial applications continued to leave the promise of

water culture unfulfilled. William F. Gericke, the man who

actually coined the term “hydroponics”, in his book The

Complete Guide to Soilless Gardening (1940), laments the fact

that “... after 1868, the conditions were as auspicious for

the birth of hydroponics as they were in 1929,” the year

Gericke began in earnest his research to find out if food

crop production using water culture could be commercially

viable.

In the next installment, we’ll explore events occurring in

the 20th century that led to the birth of hydroponics as it

is known today, as well the missteps and misinformation

that again led to its virtual abandonment as a practical

alternative method of food production for many years to

follow. 3

In an industry where dollars make sense, everyone is always looking for the next big thing. That amazing

new product that gets people excited about the industry all over again. Is it possible that powder nutri-

ents are it? It’s not like powdered nutrients are a new concept. In fact, they are the most simple, obvious,

and age old ingredient in an industry that has become over conceptualized by innovation. But sometimes,

when you get straight down to the root of things, less is more, and easier is better.

There are countless companies that have made an

attempt to get their foot in the door in the nutrient

game. Plant nutrition is an enormous industry that has

the power to revolutionize our food supply, and everyone

wants a piece of the proverbial pie. In hydroponics,

liquid nutrients have been the standard for decades, but

for growers who value efficiency, simplicity, and ease of

use, powders are becoming more and more appealing,

and appropriate – and here we evaluate a few of the

reasons why…

Dollars. Everybody wants more of them. And powders

help you save them. Whichever way you look at it,

powdered nutrients are more cost effective than liquids.

It is very expensive to ship heavy bottles of liquid here

and there, and powders eliminate that problem. Powders

give you a lot more bang for your buck, and can finally

give you more equal results than a full-on multi-bottle

liquid nutrient regimen, but don’t be fooled, because

not all powders are created equal.

Over time powdered nutrients have gotten somewhat

of a bad rap for being too crude, incomplete, insoluble,

etc., which is why liquid nutrients have always taken

center stage. However, there are a few innovative

companies that are changing the stigma, and coming

out with powdered nutrients that are revolutionizing

the industry. They are surpassing the potential of their

dry predecessors, delivering high quality, easy to use

formulas that threaten to make conventional feeding

schedules a thing of the past.

When looking for the best powdered nutrient brand,

look for one that delivers complete results. Many

powders will only offer macronutrients and require

numerous additives. However, there are companies

that produce a well-balanced and comprehensive

feeding program with one or few easy to use products.

There now exist sophisticated powder products

based on plant science that offer hybridized nutrients

with a high content of botanically-based ingredients

in combination with base nutrients, enzymes, and

biological components. These types of powders have

simplified the growing process without sacrificing the

complex needs of your plants.

Powders offer consistency. Specially-micronized

powders offer uniform precision in every feeding. It

allows growers scalability, which is very important for

growers that want to go big with less room for user

error. If someone is pouring liquid from six to eight

bottles, there is a lot more room for mistake versus

weighing out a set amount of grams of powder. Look for

a powder that is completely soluble in water, so it can

be used in every medium without leaving residue, or

clogging mechanical components.

Most water-based nutrients have a limited shelf life.

They lose their efficacy the longer the vital elements

are suspended in their liquid medium. Liquids are also

susceptible to heat and cold. Powders are not, and they

have virtually no expiration. They can be stored for a

very long time, and still offer the same powerful punch

years down the line. As soon as the ingredients in the

powder enter the water, they are activated and delivered

directly to the plant roots, optimizing nutrient uptake and

absorption. Liquid regiments require numerous bottles

because certain elements can bond together in a liquid,

leading to nutrient lockout and potential deficiencies.

Historically, powders have been associated with high

levels of heavy metals and categorized as chemically

“dirty” and inferior to liquids. Some of the companies

producing powder nutrients today are passionate about

growing, have a deep-rooted love for our industry,

for plants, and the people who grow them. They are

working hard to change that reputation.

We recognize the potential that this new generation

of powdered nutrients offers the hydroponics and

gardening industry. When you get right down to it, the

proof is in the powder. 3

However, Phosphorus is essential to life, phosphates

(compounds containing the phosphate ion PO43-)

are components of DNA, RNA, and ATP, along with

phospholipids, which form all cell membranes.

This importance shows in the hydroponics industry with

the abundance of Phosphorus containing products in every

shop, in every country. Here’s how to

spot deficiencies and over fertilisation

with Phosphorus…

Deficiencies will manifest themselves

through slow growing, weak and

stunted plants, these can be dark

green in colour with the older,

lower leaves showing possible purple pigmentation. As

Phosphorus ions are fairly mobile, Phosphorus deficiencies

will initially occur in the older leaves. This is due to the

necrotic tissue (dead patches), reddening of stems and

poor rooting.

Toxicity will show mainly in the form of a micronutrient

deficiency, with either Iron or Zinc being the first elements

to be affected due to the interaction of Phosphorus ‘out-

competing’ other elements.

A ‘What is…’ article usually focuses on the individual

elements, but because Phosphorus and Potassium are

always found together in the PK boosting products, we’d

like to include Potassium in this article of ‘What Is Are…’.

Potassium is a chemical element with the symbol K, from

the neo-Latin ‘Kalium’ and has the atomic number 19. You

may remember it as the soft silvery metal that reacted

vigorously with water in school. I remember it as the

silvery metal that destroyed the school’s toilet when we

P AND K ARE VERY GOOD FRIENDS IN THE HYDROPONICS

INDUSTRY

I hate it when people text me K, I’m very rarely in the mood to talk about Potassium via texting… I am,

however, very happy to have a good chat about it now, along with Phosphorous, because P and K are

very good friends in the Hydroponics industry, and it would be a shame to split them apart. We’ll start

with Phosphorus…

Phosphorus is the 15th element on the periodic table with

the symbol ‘P’. Due to its high reactivity, Phosphorus is

never found as a free element, because it is highly reactive.

Next time you check the back of a fertiliser bottle to see

what it has been combined with, you’ll usually find it’s

combined with other element containing minerals. Some

common Phosphorus combinations include Phosphorus

pentoxide and monopotassium

phosphate.

The discovery of Phosphorus is

credited to Hennig Brand, a German

alchemist who attempted to create

the fabled philosopher’s stone

through distillation of some salts

by evaporating urine. During this process, he produced

a white material that glowed in the dark and burned

brilliantly, it was named Phosphorus mirabilis (miracle bearer

of light). And for those that love to geek out like me,

the light emitted is called Cherenkov radiation. After its

discovery, it was used for stage lighting during theatrical

performances to light up the actors.

The first elemental Phosphorus produced was in 1669,

this was white phosphorus, which emits a faint white glow

when exposed to Oxygen. The faint white glow is what

actually gives Phosphorus its name, originating in Greek

Mythology Phosphorus means ‘light bearer’. In Latin it

means ‘Lucifer’ in its reference to the morning star (Venus,

and sometimes Mercury).

Although it is the 15th periodic element, it was the 13th

element to be discovered. It is perhaps for this reason that

it is called the devil’s element, or perhaps it’s because of its

use in making explosives and nerve agents for examples of

the most despicable acts known to man.

decided we wanted to see what a

bigger piece of potassium did… The

chemistry teacher was impressed,

the headmaster not so much. The

equation for that toilet water

reaction was as follows;

2K + 2H20 = 2KOH +H2

It was first isolated from Potash (the

ashes of plants), which is where it

also gets its name. Humphrey Davy

was the scientist that is credited

with finding Potassium in 1807 from

caustic potash (KOH – Potassium

hydroxide).

Potassium is involved in maintaining the water regulation of

the plant, the turgor pressure of its cells, and the opening

closing of its stomata. It is also required for the accumulation

and translocation of newly formed carbohydrates.

If your plants become Potassium deficient they become

sensitive to disease infestation, and fruit yield/quality will

be reduced. Older leaves will look as though they have

been burned along the edges, a deficiency known as scorch,

because Potassium is mobile in plants.

If you add too much potassium

the plant will become deficient in

Magnesium, and possibly Calcium due

to this imbalance, with Magnesium

deficiency likely to occur first. There

are good arguments for the use of

a Calcium/Magnesium supplement

during flowering periods of heavy PK

use. We will be looking at this in more

detail with Garden Culture’s next

edition of ‘What Is Are... Calcium and

Magnesium’.

There are two topics that you might

think we’ve missed in this article of ‘What Is…’ - the

relationship of P and K in flowering additives, and the

impending Phosphorus crisis. Both topics require an

article by themselves, so that gives you something to look

forward to or fall asleep to…

Thank you for taking the time to learn a little more about

Phosphorus and Potassium. But before I go, here’s one to

finish:

Did you hear about the time Oxygen and Potassium went

on a date? It went OK… No more, I promise. 3

IF YOUR PLANTS BECOME

POTASSIUM DEFICIENT THEY

BECOME SENSITIVE TO DISEASE

INFESTATION, AND FRUIT YIELD/QUALITY WILL BE

REDUCED

In many parts of the country, the killing cold of

early winter brings an end to the life of many annual

plants. When temperatures drop below freezing,

expanding ice crystals burst tender cell walls. For

some it is a swift death with the first few frosts, for

others the end of post-flowering decline, and still

others struggle on until finally succumbing to the

icy grip of cold. In order for the species to survive,

there has to be some way for the plant’s DNA to

be preserved past the life of the parent plant - for

weeks, perhaps months, until conditions improve.

Plants are notoriously “rooted in place,” inhibiting

their personal mobility. The ability to package tiny

plants into small containers allows for the use of

wind, water, animals, or people as carriers to expand

their territory beyond the physical reach of the parent

plant.

Seeds solve both these problems by being a tiny plant

(embryo) packaged with enough food to get started

with (endosperm), and secured inside a protective

covering (seed coat).

In plants that produce seeds; male flowers produce

pollen on their anthers that when applied to stigmas

of female flowers can fertilize the ovule. The pollinated

ovule forms a zygote, which grows into a tiny plant

Flowering plants (Angiosperms) use seeds (usually) as a means of reproduc-tion. Seeds are an amazing answer to some pretty formidable problems.

(embryo). The embryo will already have seed leaves

(cotyledons), stem (hypocotyl), and a root (radicle),

and be encased in a shell (seed coat). The shell helps

to protect the small plant, and allow it to go into stasis

until it finds itself in conditions conducive to sprouting.

Food stores (endosperm) may be inside the seed coat,

or outside it as is common in fruits.

To help the tiny plants inside seeds stay in a state of

suspended animation, excess moisture is allowed to

evaporate as the seeds dry out.

Depending on the type of plant

and conditions, the seeds may last

through winter, or other harsh

weather, to sprout in the spring -

or they may last for several years.

Seeds kept too wet may sprout

prematurely and then die, so seeds

should be kept in a dry container at

cool temperatures for best storage.

Germination often starts with

the reintroduction of moisture to the seed, and ends

when the plant ends its reliance on the food stores,

and can draw nutrition from the environment. The

requirements for germination are moisture, oxygen,

an appropriate temperature, and for some plants,

light. The seeds of most plants have a low moisture

content, which helps them have a long “shelf life.”

Before a seed will sprout, it must first be rehydrated.

When the seed comes into contact with moisture, it

draws in the water through a small (relatively small,

they can be easily seen on coconuts for example) holes

(micropyles). This moisture will cause the plant to

swell, and soften the seed coat, allowing the radicle to

break through using hydraulic pressure to seek more

moisture, and the seed leaves to swell and open to

seek out light.

One way to help with getting moisture through the

micropyle, is to soak the seeds in water for 24 hours.

Another is known as “scarification” helps to weaken the

seed coat, and allow the plant easier access to moisture.

This involves nicking the seed coat

with a sharp object, or rubbing the

seed on a rough surface, such as

sandpaper or an emery board.

Moistening a paper towel, wringing

it out, and putting it with seeds in

a plastic bag in a warm location

to sprout is another way to aid

moisture in saturating the seed.

If using this method, change the

paper towel every few days to

keep it fresh, as it is an environment conducive to

germinating plant seeds, but mold spores as well.

Once a seed becomes waterlogged, fungus can set in

and ruin it.

The amount of oxygen needed by a particular type of

plant varies. Some plants will not germinate even in the

presence of moisture, unless air is also present. For

this reason, most seeds should not be soaked directly

in water for days on end, but transferred to a better-

aerated environment after an initial day or so.

mo s t s e e d s shou ld n ot b e s o ake d i n wat e r for d ays on en d

Moist seeds will germinate at a

temperature of 68°-86°F (20-30°C),

with 75°F (24°C) being ideal for many

plants. In cold settings, a heating pad

may be used to raise the temperature

of seed trays.

Some seeds germinate better in light,

and others in dark conditions. Check

the information about the type of seed

to learn which it prefers.

Many seeds can be sprouted by simply

burying them 3 to 4 times their width, and kept moist,

but not soggy, until sprouting. To prevent the media

from drying out too quickly, sometimes domes or

plastic sheets are used to keep the humidity high while

seeds sprout. However, do not allow the seedlings to

stay too wet for too long, or fungus may start to grow

on the plant near the media, causing the fatal condition

known as “damping off.” Media should be “moist” - not

“wet.” Do not allow the media to dry out too much,

however, as once the plant has germinated, it loses its

ability to survive without water, and with such a small

root system, it can quickly dry out and die.

Quality harvests depend on quality seeds, whether

purchased, gifted, or gathered. Seeds from many plants

can be collected, and used the following year. If the

seeds are going to be collected, for predictable results

“open pollinated” varieties should be used. These seeds

will tend to produce similar plants from one year to the

next.

In late winter to early spring, it is

common to start seeds indoors

to be prepared for spring planting.

To determine when to start your

outdoor garden seeds indoors, find

out the date of the last frost in your

area. Then read the seed packet,

which should tell you how many

weeks before the last frost date to

start them.

Some plants have an additional concern

when calculating their planting dates, photoperiodism,

which means that they use the duration of their dark

periods to determine when to flower. Spring and

fall both have longer nights than the short nights of

summer. These plants bulk up during the summer, until

the longer nights of fall trigger flower, or fruit set. The

reason that this can be a concern, is that if these plants

are set outside in the spring months when the nights are

long, they can immediately begin flowering.

Depending on your area and need, it is common to start

seeds indoors 6-8 weeks before the last frost date.

Plants started indoors should be “hardened” by moving

to a sheltered location, or gradually increasing the

time the plant spends outdoors. This allows the plant

to become used to the new conditions over time, and

minimizes the shock from the change.

Starting plants from seeds can be rewarding, and cheaper

than purchasing established plants. As an additional

bonus, starting seeds indoors can extend the gardening

activity months. 3

It i s c o mm on

t o s t a r t s e e d s

i n d o or s 6 -8 we ek s b efor e th e l a s t fr o s t

d at e

Rooting cuttings is a time

honored tradition that allows

for certain plants to be propagated

asexually. It effectively allows the same plant

to be grown in multiple pots. Since the new plant

shares the same DNA as the parent plant (barring mutation)

it is commonly referred to by the term “clone”. Cavendish bananas are all

clones of the same plant, most wine and table grapes are clones, so are practically

all potatoes, and the grafts for commercial fruits and citrus.

group of cells that formed the branch that the cutting has

been taken from were mutated, then the branch may be of

a different genotype than the rest of the plant, and cuttings

taken from that branch will also be different from the

rest of the plant (but the same as other cuttings from the

affected branch).

Cuttings are able to form roots from stems and growth

nodes by using a type of plant cell known as a meristem

cell. These are undifferentiated cells that can mature into

a variety of adult cells depending on the environment that

they are exposed to. The growth tips in plants have so many

meristem cells in them that they are known as shoot apical

meristems. The meristem cells in the growth tips mature

into shoot and flower cells, adding to branch length, leaf

development, flowers, and fruits depending on which type

of cell is called for.

Another high concentration of meristem cells can be

found in the root tips, which are also known as root

apical meristems, which mostly mature into root cells.

It is important to note that the meristem cells found in

the growth tips, along the stem, and in the roots, are all

exactly the same, and it is the conditions around them that

determine what they eventually develop into.

Cuttings are generally taken during the most vigorous part

of the plant’s growth cycle, but before flowering starts.

Since the parent and the cuttings share the same DNA,

they will be the same genotype, if grown under similar

conditions, that will tend to express as similar phenotypes

(the directly observable attributes of the plant). So a cutting

from a yellow flowered plant will also have yellow flowers,

and a cutting from a female plant will also be female. This

can be used to good effect when a lot of the same color

flower is desired in varieties that have a variety of colored

flowers.

This method of propagation can also be used when

determining gender, as a cutting can be taken, and

exposed to a flowering light schedule while the parent

is left under growth lighting (or vice versa). Whatever

gender the parent shows will also identify the gender of

the others. Clones can be useful to propagate a number

of plants with the same characteristics, such as when a

roomful of relatively identical yellow flowered female

plants is desired.

Cuttings from plants grown from cuttings have the same

DNA as the original plant. Usually, anyway, if the original

I n d ole but y r i c a c id or

n aphth a len e a c e t i c a c id en c ou r a g e

r o o t d evelopm ent

prevent the cutting from suffering

from terminal wilt (which will kill

it), keep the cut end in water

until it is ready to be used.

Before putting in the rooting

medium the ends of the cuttings

can be exposed to a plant auxin hormone, such as

indolebutyric acid (IBA) or naphthaleneacetic acid (NAA),

to encourage root development. Both are frequently

applied in the form of a rooting powder, gel, or liquid.

The stem end of the cutting is placed into a mild potting

soil, oxygenated water, or other suitable medium in a warm

location under moderately bright lighting. If a solid medium

is used, it should be kept moist, but not soggy. If over

watered, the end of the stem may develop a fungal infection

and rot. Under favorable conditions, roots will generally

appear within a week or two, although some plants like

tomatoes can root within a few days, and some plants may

take a month or more. As long as the shoot portion of the

plant is kept healthy, and there is no indication of root rot,

the chance still exists for a particular cutting to form roots

eventually.

Rooting cuttings is mostly a matter of getting conditions

right, and perseverance. Some plants root easier than

others, but being able to propagate asexually via cuttings is

a handy tool to add to a gardener’s skillset. 3

Grafting is basically taking a

cutting and placing it into a

matching cut in a rootstock

plant. The meristem cells in this

case grow to heal the cut. This

may be done to match superior

rootstocks with superior fruiting varieties, or as in the case

of citrus, seed grown trees may take 10 years to mature

enough to grow fruit, but a cutting from an existing older

tree grafted onto fresh rootstock can produce fruit in a

couple years. This is because the cutting and resulting

growth from the graft is already old enough to produce

fruit.

Meristem cells are also critical when using tissue culture

techniques, as their ability to mature into any type of adult

cell can be manipulated into making a complete plant from

a tiny cutting.

For a normal cutting to be grown into a complete plant,

it should include a shoot apical meristem (growth tip,

or at least a budding site) and a section of stem. It is the

meristem cells in the stem and any lower budding sites that

are induced to develop into root cells, and create new root

tips.

When taking cuttings from a plant, the cut should be neat

and clean, as it will make a wound in the parent plant. To

In the series “Light Matters”, Theo Tekstra discusses different aspects to lighting,

such as quantity, quality, efficacy, special applications, new developments, and

the science behind it. In this first episode we focus on quantity. How much

light do you give your plants? And how does that matter?

reaching a surface of a square meter every second.

This is called Photosynthetic Photon Flux Density, or

PPFD.

Unfortunately, photons are so numerous that that

would easily lead to a 20 digit number, which is a bit

hard to read and value. There is, however, a standard

unit of measurements which defines a large number

of particles such as atoms, molecules, electrons, and

photons. It is the mole. By all means, if you want to

learn more about moles, take a look at Wikipedia,

but for now, it is enough to know that 1 mole of light

is 6.22 x 1023 (the Avogadro number) photons.

The notation for mole is mol, just like ‘s’ is for second,

and ‘m’ is for meter. As we already saw light intensity

is Photosynthetic Photon Flux Density, which is moles

of light per square meter per second. The scientific

notation of “per square meter per second” is “m-2

s-1” - so for space’s sake, and to make it look real

scientific, we are going to use mol m-2 s-1 from now.

Full Sunlight at midday is about 0.0025 mol m-2 s-1, or

2.5 millimol m-2 s-1, or 2,500 micromol (µmol) m-2 s-1.

I think you will agree with me that the µmol m-2 s-1 is

the easiest to use here. Which is fortunate, because

this is the way we measure the photosynthetic

photon flux density.

To recap:

• Photons are so numerous that we count them in

moles of photons.

• Photosynthetic Active Radiation (PAR) is defined

in the range between 400 nm light (blue) and 700

nm (red).

• Light intensity is defined as the number of PAR

photons per square meter per seconds, so mol

m-2 s-1. In practice, we use µmol m-2 s-1.

Plants are Photon CountersPlants use photon strikes for the synthesis of chemical

energy, such as sugars. I say strikes, and not light energy,

because it is the number of photons that is primarily

responsible for the process, and not the individual varying

energy of those photons. Blue photons for example,

contain a much higher amount of energy. That extra

energy, however, is mostly dissipated into heat. To bind

a CO2 molecule, you need about 8-12 photons. So, you

see it is a numbers game! We need to know how many

photons hit our plants to get an idea of the total potential

photosynthesis.

Plants are photon counters. Look at photons as rain

drops: the lighter the rain, the less water reaches the

surface. It’s the same for light: the fewer the photons, the

less light plants get for photosynthesis.

Counting LightTo quantify grow light, we first need to establish which

photons to count, and how to express that in numbers.

It has been established that photons with a wavelength

ranging from 400 nm (blue) to 700 nm (red) contribute

most to the photosynthetic process. That is why we call

photons in this range Photosynthetic Active Radiation, or

PAR for short.

In order to quantify a stream of particles, we need to

count how many reach the surface, at a given time, on

a standard size surface. The international standards for

time and surface are second and square meter. Taking

this back to raindrops again: the rate of the raindrops is

defined by the number of raindrops that fall on a square

meter of surface in one second. It gives you the density

of the rain.

The same applies to light: the intensity of the

(photosynthetic) light is defined by the PAR photons

Amount of Light Per DayA light rainfall that continues for 20 hours can result in

much more water than a short heavy shower. There is a

relationship in the intensity of the rain, the length of the

shower, and the amount of water that reaches the ground.

The same goes for light: the total amount of photons

reaching your crop is based on the intensity of the light,

and the light period. The intensity, or PPFD, is defined as

mol m-2 s-1, so by multiplying this by the number of seconds

to get this intensity per day, you get the number of photons

per day, expressed in mol m-2 d-1 (moles per day). This is the

DLI - ‘daily light integral’.

Let’s work on an example.

- PPDF is 1000 µmol m-2 s-1

- Light period daily is 12 hours in a 24 hour cycle

To convert PPFD to DLI, multiply by the number of seconds

you are lighting your crop:

1000 (µmol m-2 s-1) x 12 (hours) x 3600 (seconds per hour)

= 43,200,000 µmol m-2 d-1, or 43.2 mol m-2 d-1.

And there you have it. The relationship between the light

intensity, and the amount of light per day.

Questions and AnswersArmed with this information, let’s try to answer the

following questions:

Q: If I give half the intensity of light, and double the time the

plants get it, does that have the same effect on photosynthesis?

A: Yes, it does. This is how we light tomatoes and roses in

greenhouses. They are long day plants (which flower and

fruit when there are long days of light), and they get up to

20 hours of light per day on dark days. However, if you are

flowering short day plants (which flower when the nights are

long), there is a limited period of about 12 hours in which

you can give that to your plants. So, in that case, you will

use a higher PPFD to get the same DLI in a shorter period.

Q: So basically for a higher yield, I should just give more light?

A: Yes, but there is an optimal and maximum amount of light

per day, and also a maximum intensity you can give your

plant. A shade plant, for example, can only take a limited

intensity, and short day plants do have a maximum intensity

and DLI. It is also a function of what we call the limiting

factors for photosynthesis:

- Light

- Carbon Dioxide

- Temperature

Here is a graph representing the three limiting factors:

These three have to be in a balance. When there are one or

two too low, it will cause the plant to perform sub-optimally,

and there are absolute maximum and optimal levels as well.

So more light might require a higher temperature, and/

or more CO2. It is the grower’s mission to find the right

balance for his crop, and this is just one of the balances.

Other factors are the climate (as in humidity, for example),

available water, and nutrients.

Q: What is the optimal PPFD to give my crop in an indoor

environment?

A: For that you need to know the photosynthetic response

curve of your plant, and you need to make a choice -

whether you want to harvest as much crop per invested

energy (grams per Watt), or crop per square meter (grams

per square meter). It requires an experienced grower to

do the last, as you will be growing up to your plant’s limits.

Let me explain this with a diagram, showing photosynthesis

(Pn) against irradiation (I) of a specific crop (for other

crops this may

be different). A

second variable

in this graph is

temperature:

At low intensity, you see a more linear increase of

photosynthesis when the light intensity increases.

However, with increased light levels, at some point the

photosynthesis tapers off, and at a certain level may even

cause photoinhibition. So doubling the amount of light does

not automatically mean that you will have double the amount

of yield. For every temperature, there is a saturation point:

a point where adding more light will no longer add to extra

photosynthesis. The saturation point is lower at a high

temperature, but the efficiency of the applied light is much

higher at an optimal temperature. Hence, you need to grow

at the right temperature to get optimum effect from your

light, 30°C in this example.

Remember the limiting factors of photosynthesis? The

moment you see the curve tapering off, you have reached

a limiting factor. In this case, temperature and PPFD were

variable, while CO2 is a constant. Adding CO2 will give you

a longer linear curve, so a much higher photosynthetic rate.

Q: Should I use the same PPFD during the vegetative stage of my

short day crop?

A: Using the same PPFD in the vegetative and flowering phase

will result in your crop getting 50% more light (higher DLI)

in the vegetative phase when you light it 18 hours in veg, and

12 hours in flowering. Reducing your PPFD in veg by 33% will

result in the same DLI. So, if you flower with 1000 µmol m-2

s-1 for 12 hours, giving your crop 667 µmol m-2 s-1 for 18 hours

will result in the same amount of light per day.

MORE LIGHT MIGHT REQUIRE A HIGHER

TEMPERATURE, AND/OR MORE CO2

Q: How about supplemental lighting in greenhouses? How much

do I need?

A: That depends on the DLI of the sunlight throughout the

season you grow, and your crop. The DLI you get from

natural sunlight depends on your geographical position.

Purdue University published a good overview of DLI during

different seasons in the USA:

Source: http://bit.ly/purdue-DLI

However, that is not the DLI your crop will receive in the

greenhouse:

• During a clear sky summer day of full sun you will

probably shade your plants, because the PPFD is too

high, reducing the DLI of the sunlight.

• Your greenhouse construction takes away light.

Transmission losses can be as high as 25%, or more.

Secondly, you need to know the optimal DLI for your crop,

and whether you are going to give this in a long day, or a

short day. For a short day crop, the time that you can light

your crop is limited. The light level will need to be higher

than for a long day crop, which you can light for a long time

to compensate low sunlight DLI. 3

Garden Culture Magazine: UK 11

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