The Virtual Gardener—How to Know the Mesquites

Vol. 24, No. 11 November 2013

The University of Arizona and U.S. Department of Agriculture Cooperating

High on the Desert Cochise County Master Gardener Newsletter

Cuttings ‘N’ Clippings 2

Did You Know . . . 2

Pest Management 3

In a Desert Garden 4

November Reminders 4

Ask a Master Gardener 4

At a Glance Box 5

Desert Broom 5

UASV MG Project 6

Inside this issue:

Cochise County Cooperative Extension

www.ag.arizona.edu/cochise/mg/ 1140 N. Colombo, Sierra Vista, AZ 85635 450 S. Haskell, Willcox, AZ 85643

(520) 458-8278, Ext. 2141 (520) 384-3594

Love’em or hate’em, mesquites are

one of the signature trees of southeast-

ern Arizona. They come from the

Fabaceae (or legume) family and are

members of the genus Prosopis. The

genus originated either in Africa, where

one of the most primitive species of the

genus (P. africana) is found, or in

Argentina. In any case there are three

native population clusters. One in

Africa and the Middle East, and two in

the New World—one in Mexico and

the Southwestern United States and

another in Argentina, Paraguay, and

Chile. But mesquites have now been

introduced by humans into almost

every arid and semi-arid region of the

world, including Southwest Asia,

Australia. and Hawaii.

Mesquites are widely distributed in

the United States, ranging east-west

from Arkansas and Louisiana to

California and north-south from

Nevada, Utah, and Colorado to the

border with Mexico. They are especial-

ly widespread in the Chihuahuan,

Sonoran, Mojave, and Colorado deserts

where flat open areas may be heavily

populated with mesquite shrub thickets

and desert washes lined by larger

specimens.

According to the Online Etymology

Dictionary, the name "mesquite” comes

from the Mexican Spanish word

“mezquite,” which in turn comes from

an Aztec (Nahuatl) word “mizquitl.”

For some obscure reason now lost in

time, the genus name, Prosopis, is

derived from the Greek name for

butterbur (Petasites hybridus), a

medicinal herb that was once thought to

protect against the plague.

Mesquite taxonomy is confusing. The

International Legume Database and

Information Service (ILDIS) lists a

total of 111 species names for the genus

Prosopis, worldwide, but only recog-

nizes 46 of them as legitimate. Until

relatively recently two of the native

mesquites in the United States were

considered to be different varieties of

one species—juliflora. It is now

recognized the P. juliflora is an entirely

separate species native to Central and

South America.

(Continued on Page 2)

Cuttings ‘N’ Clippings Local native mesquites come

in three basic flavors—honey

mesquites (P. glandulosa in two

varieties: var. glandulosa and

var torreyana), velvet mesquite

(P. velutina), and screwbean

mesquite (P. pubescens). Also

widely grown here as ornamen-

tals are two imported varieties—

Chilean mesquite (P. chilensis)

and Argentine mesquite (P.

alba). A third import, harder to

find in the stores and less

commonly grown, is the black

mesquite (P. nigra), also from

Argentina. Because mesquites

are quite promiscuous and easily

cross pollinate, pure species are

hard to find in stores. Many

nurseries don’t even try to keep

them straight and simply refer to

them as “hybrid mesquites.”

Common hybrids are mixes in

various proportions of velvet

mesquites, Argentine mesquites,

Chilean mesquites, and perhaps

others.

Mesquites are optimized for

survival in arid desert environ-

ments, which makes them

superbly suited for use as

ornamentals in xeric desert

landscapes. Many are formida-

bly armed with sharp thorns that,

according to J. Frank Dobie, will

remain indefinitely embedded in

flesh without decaying, which

deters munching of the foliage

by grazing animals. Their com-

pound leaves are divided into

many small, wax-coated leaflets

that resist dehydration. Their

flowers are especially attractive

to pollinators, and they produce

a prodigious quantity of seeds.

The seeds are wrapped in sweet

pods that are favorite foods of

many herbivores (and even

coyotes, according to one

(Continued from page 1)

The next CCMGA meeting will

be held Thursday, November 7 at

5:00 p.m. in the Public Meeting Room

located in Groth Hall at UASV. Just

because leaves are falling doesn't

mean your winter garden has to be

bare and without color. Our speaker,

Master Gardener Jan Groth, will talk

on Plants for Winter Interest, discuss-

ing the many desert adapted and native

plants with winter personality. We'll

also touch on winter pruning for

spring performance. As always, we

welcome the public to attend!

Water Wise will hold a talk on

Septic Care at UASV in the Public

Meeting Room located in Groth Hall

on November 16 from 9:00—11:30

a.m. The presenter will be Dr. Kitt

Farrell-Poe, UA Water Quality Spe-

cialist. For information call (520) 458-

8278, Ext 2141, or contact Joyce at:

jwilliam@ag.arizona.edu/

You can visit Water Wise at:

waterwise.arizona.edu

P A G E 2

Did You Know . . .

By routing recyclable materials to

the blue bin instead of the green gar-

bage cans, Sierra Vista residents have

kept 168 tons of trash out of the land-

fill each month! If you live in Sierra

Vista and don’t have a blue recycling

bin and would like one, contact Sier-

ra Vista Public Works at 458-5775 or

visit the website at

www.sierravistaaz.gov and search

for “curbside recycling”—the bins

are provided to any residential refuse

customer free of charge.

-Vista 411/Oct-Nov 2013

report). The pods are digested and

their enclosed seeds dispersed in

the feces of the animals that eat

them. Individual seeds are

armored with a protective coating

that allows them to remain viable

after lying dormant for many

years waiting to be activated

when environmental conditions

are just right or they have been

scarified by passage through the

digestive systems of animals.

According to the Arizona-Sonora

Desert Museum mesquites

coevolved here with Pleistocene

(Ice Age) megafauna such as

mastodons and giant ground

sloths that consumed the seeds

and dispersed them widely. Cattle

herds, introduced by Europeans

many years later, served the same

purpose, causing the trees to

become widely spread. Lastly,

mesquites have extensive root

systems that not only efficiently

harvest water but host nitrogen-

fixing bacteria that provide a

source of this vital element in our

impoverished soils.

Although they may sometimes

be confused at first glance with

some of their cousins in the

legume family—acacias and

mimosas—mesquites are quite

easy to identify as a group. But

taking the identification to the

species level can be tricky. Pure

species may be distinguished by

form, color, bark, foliage, and

other characteristics, but hybrid-

ized trees may have mixed

characteristics from two or more

species making specific identifi-

cation very difficult. Click here

for a handy guide to mesquite

species identification.

Until next time, happy surfing!

Gary Gruenhagen, Master Gardener

virtualgardener@cox.net

ease and insect resistance, so pay

attention to these characteristics the

next time you shop for seeds.

Healthy plants are another key to

minimizing pest damage. To begin

with, pick nice specimens if you’re

buying at a nursery. Root bound

plants or plants that “look bad”

won’t give you a good start to a

healthy garden. Weakened plants

seem to attract pests looking for an

easy meal. Remember, plant health

begins with healthy soil, so build

your soil up with organic matter and

compost. Organic matter also helps

retain moisture, a real plus here in

the arid high desert. Keep your

plants adequately watered and

quickly remove diseased plants

from the garden to inhibit disease

spread. Make sure your plants are

adequately fertilized, whether you

practice organic or conventional

techniques.

Good management techniques are

another way to beat the critters.

Plant at the proper depth and time of

year, space plants adequately to en-

sure good air circulation and mini-

mize hiding spots for troublesome

pests, prune plants that require prun-

ing. If you have a lawn, keep it

mowed to deprive insects of easy

hiding spots.

Finally, keep a good journal on

your garden. Record information

such as planting dates, varieties

planted, germination times, harvest

dates, and any significant observa-

tions made through the growing sea-

son. Then, and here’s the key, RE-

VIEW your journal occasionally.

Learn from your successes and mis-

takes. The bottom line is this: doing

just these few simple things can en-

hance your garden yield and quality.

Happy gardening!

Bill Schulze, Master Gardener

billwithccmga@gmail.com

don’t plant related species in the

same spot more than once every

three or four years.

Frequent inspection of the gar-

den is key to preventing pests from

getting out of hand. Just because

your tomatoes won’t be producing

for a few more weeks doesn’t

mean you don’t need to check

them frequently. Hornworms, for

instance, are extremely easy to

control by hand picking, but if

they have a week to chew on your

‘mater plants before you find

them, you’re likely to find a toma-

to plant with no leaves left and

that ain’t a path to plentiful tomato

yields or tasty BLTs.

Another great and very easy way

to prevent problems is to select

varieties that are resistant to a par-

ticular pest or disease. For in-

stance, many squash varieties are

susceptible to squash vine borers,

but some are not. A species of

squash that is vine borer resistant

is Curcurbita moschata. This spe-

cies encompasses a number of

popular squash varieties from zuc-

chini types such as ‘Trombon-

cino’ (aka ‘Zuccheta’) to winter

squashes such as ‘Waltham Butter-

nut’, not to mention a number of

pumpkin varieties. Most all com-

mercially grown squashes canned

and sold as “pumpkin” are of the

C. moschata species. Insect (and

disease) resistant varieties can be

found for pretty much every type

of vegetable you care to grow.

Seed catalogs frequently tout dis-

In my experience, insect pests

have not been a significant prob-

lem in the vegetable garden.

Don’t get me wrong, I’ve defi-

nitely lost my share of plants to

insects. Squash vine borers have

destroyed my zucchini more than

once, grasshoppers wreaked hav-

oc with my greens last fall, and

cucumber beetles always make

growing tomatillos a real chal-

lenge. Still, enough crops are suc-

cessful in any given season to

make the garden an overall suc-

cess. Nonetheless, there are a

number of simple things we can

do to improve our odds of defeat-

ing insect pests and plant diseas-

es.

High on the list of things we

can, and usually do, is to have a

diverse garden. A garden with not

only multiple vegetable crops, but

also herbs, shrubs, flowers, and

trees increases the kinds of habi-

tats necessary for insect predators

to live there. Whether those pred-

ators are other insects, arthropods

such as spiders or birds, having

them living in our garden is a real

plus. Encourage predators by

practicing plant diversity.

Another important thing garden-

ers should do is practice crop ro-

tation. Rotating crops from spot to

spot within the garden helps pre-

vent soil borne diseases from get-

ting well established. It also de-

feats insects that lay eggs or oth-

erwise overwinter in the soil, right

there under their favorite food. Do

be aware of the family groups of

vegetables. For instance, toma-

toes, peppers, eggplants, and po-

tatoes are all members of the Sol-

anaceae family. Cabbages, kale,

broccoli, cauliflower, and many

others are all members of the

Brassica family. Learn these veg-

etable family relationships and

P A G E 3

Pest Management in the Home Garden Janyce

Cochise County Master Garden-

ers are available to answer your

gardening questions either by tele-

phone call to the Cooperative Ex-

tension Office or on-line on our

web site at:

www.ag.arizona.edu/cochise/mg

The following comes from our web

site’s Frequently Asked Questions:

Question: Should I fertilize and

water my outdoor plants during the

winter?

Answer: Fertilizing of trees and

shrubs during the winter in the

high desert should not be done.

Fertilizer could stimulate plants to

come out of dormancy, start new

growth and winter damage could

occur. These plants are "resting"

above the ground but do have ac-

tivity in the roots if soil tempera-

tures are warm. Normally trees and

shrubs that go into winter with ade-

quate soil moisture do not need

watering during the winter. Usual-

ly winter rains or snow provide

enough water. Deciduous plants do

not need much water because the

leaves, where transpiration occurs,

are gone and nutrients needed for

growth are not required because

there is no shoot growth. The same

holds true for most evergreen

plants. When the air temperatures

are cold and sunlight is reduced,

why grow? However, if winter

moisture is not sufficient to keep

the roots moist they will die. If no

winter moisture occurs for four to

six weeks then water.

P A G E 4

Ask a Master Gardener

Cochise County Master

Gardener Newsletter Editor

Carolyn Gruenhagen

This is a good time to install

a drip system

Replace summer mulch with

fresh mulch

Start a winter herb garden

Protect plants from frost—see

publication at:

http://ag.arizona.edu/

pubs/garden/az1002.pdf

In a Desert Garden

Arizona Goldeneye

Viguiera

Fall is the season when Arizona

Goldeneye shines. This is a spec-

tacular plant, especially when

grown in masses. This is a plant in

the sunflower family—Compos-

itae. There are eight species of

Viguiera in Arizona; some are per-

ennials and some are annuals. The

one that grows in my yard is the

annual, V. annua. This is a plant

that has just arrived in my yard, as

so many others have. I have never

seen one available in the trade.

The perennials form shrubby

bushes to four feet tall and wide.

Here in southern Arizona I have

seen mostly the annual variety. A

few weeks ago, when I was in

Bisbee on Naco Road, I came

across a field with nothing but Ari-

zona Goldeneye. That was an im-

pressive picture. Of course, I had

no camera with me. I was in that

area two weeks later and the flow-

ers had faded. Unfortunately, the

show doesn't last too long.

This plant loves water, that is

why, all of a sudden during the

monsoon, the plant appears, sets

flowers, and fades with the end of

the monsoon. In my yard it stays

attractive a little longer as it re-

ceives some irrigation.

Goldeneye can grow to four feet

tall, depending on water and soil.

The plants in my backyard are tall-

er and more vigorous as there the

soil has been amended and more

water is available.

This is a very dainty plant with

slender stems and thin long lance

shaped green leaves, heavily

branched, and has a gazillion small

yellow sunflower-like flowers with

darker centers. It attracts many

insects like bees and butterflies.

The only downside to this plant is

that it usually grows where it

doesn't belong, growing where the

seeds fall, usually between other

ornamentals. But the show is so

breathtaking and short-lived, I let it

be and enjoy it while it lasts.

Angel Rutherford. Master Gardener

Photographer

P A G E 5

Issued in furtherance of Cooperative Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, Jeffrey C.

Silvertooth, Associate Dean & Director, Economic Development & Extension, College of Agriculture and Life Sciences, The University of Arizona. The

University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.

The information given herein is supplied with the understanding that no discrimination is intended and no endorsement by Cooperative Extension is implied.

Any products, services, or organizations that are mentioned, shown, or indirectly implied in this publication do not imply endorsement by the University of Arizona.

At a Glance Box

It’s a Bloomin’ Cochise County Native Plant of the Month Plant: Desert Broom, Baccharis sarothroides

Description: A woody, evergreen shrub

Blooms: Fall

Use: Male plant, hedge, evergreen Xeriscape choice

Culture: No supplemental water. Hardy.

Learn more: Cochise County Herbarium,

http://www.cochisecountyherbarium.org/plant.php?cat=dbsn&item=778

For an in-depth article on Desert Broom, see below

Cado Daily

Water Resources Coordinator, Water Wise Program

University of Arizona Cochise County Cooperative Extension

Desert Broom Baccharis sarothroides

The females are the problem.

They are more prolific than rab-

bits. (Please note, this author is a

female so I take full responsibility

for any sexist comments!) But no,

I am not describing human behav-

ior. I am describing the female

plant Baccharis sarothroides or

more commonly known as “desert

broom.”

For those who do not know the

plant, it is an evergreen, indige-

nous shrub that doesn’t look like

it has any leaves, is about four

feet wide by five feet high and is

rather, well, prolific. For those

who do know the plant, I am sure

the majority of you are saying,

“Aurgh! Desert broom—get rid of

it!!” But hold-on, let me shed a

little light on this under-

appreciated plant.

If you look carefully at several

different shrubs when they are in

bloom (Oct-Nov), you will notice

that the flowers are different. You

can even tell from a distance (even

from the car) that some plants have

a dirty yellow look, while others

are whiter. Up close, you will see

flowers with white fluff on some

plants and small almost ball-

shaped dirty-yellow colored flow-

ers on others. It is because these

plants are dioecious—meaning that

there is a male plant and a female

plant. When the male plant is in

bloom, you will see that there are

beetles, butterflies and other as-

sorted flying beauties that visit the

dirty yellow-colored flowers.

In November, the female plant

releases her seeds and the white

fluff flies all over the place. At that

time it is common to hear people

complain about an allergic reaction

to the plant. I think we can safely

say that the male plant isn’t a cause

of the reaction since it produced

pollen in October (and since it gets

covered in insects it implies that

the plant is insect pollinated and

not wind pollinated). Although the

female seed fluff is rather large for

getting up a nose, perhaps the

achenes (the fluff on a seed that

helps with wind dispersal) break

up into smaller pieces and are

transported by the wind.

What can cause some reactions

in people year-round is the slight

stickiness of the plant. Dust, pol-

len, and other irritants can stick to

the stems, and the resin itself may

cause an allergic reaction.

However, the positive attributes

of the male plant are good

enough that a groundcover

“trailing desert broom,” Baccha-

ris hybrid, has made its way into

the nursery trade and is a favorite

with some landscapers. Even the

local upright species can make a

great evergreen landscape plant,

or even a hedge. The fact that it is

so hard to get rid of makes it a

great no-care, no-water plant

where you do want it! To keep

the plant from getting too woody,

some light to severe pruning can

be done in late winter.

So before you attack the desert

broom in your yard, take a second

look. If it is an attractive male,

you may want to keep it.

Ms. Cado Daily, M.A.

Water Resources Coordinator

Male Desert Broom

P A G E 6

CCMGA Project at UASV

The Cochise County Master Gardeners

continue to expand the demonstration/

teaching gardens on the UASV campus now

to the east front patios of Groth Hall. Look-

ing good!

Planning a project that involves digging?

Know what’s below—call before you dig!

811