Building the Propagation Environment

LAT 109

What does the propagation environment have to do?

• Depends… on what you’re propagating and where you are.

• Hardwood cuttings

• Softwood and semi-hardwood cuttings

• Seed propagation

For semi-hardwood and seed prop

• Provide a low-water loss environment– High humidity

• Provide protection from the elements– Cover

• Provide light (but not too much)– Open, but shade if necessary

• Provide a temperature conducive to rooting (germination)– 70 to 75° F

Key features

• Structure• Cover• Raised bench• Drainage• Intermittent mist• Bottom heat• Light/shade system

Structure

• Glass house• Hoop house• Cold frame• Outdoor beds• Other?

Cover

• Clear 6 mil poly is commonly used

• Polycarbonate

• Glass

Raised benches

• Provide better drainage and an ergonomic workspace.

• Sanitation is easier.

Drainage

• Ground cloth• Gravel• Permeable pavers• Concrete (with drain

tile)• Proper grade• Critical if propagating

on the ground!

Intermittent mist

• Water source• Piping• Nozzles• Mist timer• Day timer• Turn on in the morning,

turn off at night• Every 8 minutes for 8

seconds is typical

Bottom heat

• Electric– Cables– Mats– Thermostat

• Water• Goal is ~70°F

Light/shade system

• Shade cloth– Summer– Reduce UV– Reduce temperature– Sold by % shade– Automated systems

• Supplemental light– Induce flush of growth– Tricks the plant into

thinking long days (short nights)

Light interruption to induce growth

Winter = short days and long nights = minimal growth

Summer = long days and short nights = growth

Light interruption = short nights = growth

Avoiding diseases• Major pathogens– Soil born pathogens– Root rots – “damping

off” or “foot rot”– Water molds• Pythium (wet & cool)

and Phytophthora (wet & cool)

– True fungi• Rhizoctonia (wet &

warm) and Fusarium (variable)

Strategies

• Cultural– Disease free plants– Clean tools– Clean facilities– Clean containers

• 10% bleach

– Sterile media– Work in a separate area

from mist bench– Environmental conditions– Monitor daily

• Chemical– Fungicide

• Soak cuttings prior to sticking

• Drench beds after sticking

– http://ipm.illinois.edu/diseases/rpds/615.pdf

Conifer cutting propagation

Easy-ish to propagate conifers

• Cupressus• Chamaecyparis• Thuja• Juniperus• Thujopsis• x Cupressocyparis leylandii• Taxus• Cryptomeria• Tsuga• Calocedrus

Types of conifer cuttings

Our protocol today• 4 to 8 inches long terminal (tip) cuttings with some wood are most

often used. However, you can try heel and mallet cuttings as well.• Remove foliage from lower half• Trim foliage (tops) if necessary• Basal wounding can help• Using Wood’s rooting hormone (1.03% IBA), we’ll want to mix up 10 oz

of 3000 ppm IBA to be divided among the benches for our 5 second quick dip. How much Wood’s do we add to how much water to get 10 oz of a 3000 ppm IBA solution?

• Insert ~ 2 inches into propagation media• e.g. Cupressus, Chamaecyparis, Thuja, Juniperus, Thujopsis,

× Cupressocyparis leylandii, Taxus, Cryptomeria, Tsuga, Calocedrus• Today we’ll use the 6-cell packs for our conifer cuttings. Each student

is to stick a minimum of 12 cuttings (2 packs per person)• Remember: 10% bleach to sterilize pots, 1:2 peat:perlite media,

LABELS, all cuttings go on the mist bench in the West greenhouse.