What I’ve Learned About Xeriscape: Are Your Plants in the Right Zone

1. VOL. 11, NO. 11 The University of Arizona Cooperative Extension NOVEMBER 2000
8XVW^]cWT4TbTac
Cochise County Master Gardener
Tfb[TccTa
The University of Arizona and U.S. Department of Agriculture cooperating.
What I’ve Learned “xeros” meaning dry and “scape” health. It’s a simple concept. By
meaning vista and therefore the grouping plants with similar irriga-
About Xeriscape – definition of “water conservation tion frequency and duration require-
through creative landscaping.” ments, the irrigation schedule is
Are Your Plants in Here’s a fun fact. While doing re- planned accordingly to water plants
the Right Zone? search on Xeriscape I discovered when they need it.
that the word has been trademarked
Many people who visit my garden and the x should always be For example, say a planting area
are surprised to find out, with the capitalized. consists of an Agave parryii, Acer
exception of the vegetable and herb species (Maple), Chilopsis linearis
garden, that it is a “Xeriscape” I have been practicing (a kind (Desert Willow), Dalea pulchra
garden. It is full, lush, and attracts word for trial and a lot of error!) (Bush Dalea), Penstemon superbus
birds, butterflies, and other desert the Xeriscape Principles and Zones (Superb Penstemon), Salvia cleve-
insects and animals I am fond of. for the past six years. I love and landii (Chaparral Sage), and group-
In 1999 my garden required eight embrace them because they are the ings of Zinnias. They are all on one
irrigations and so far this year five. tools for a “maximum results with irrigation line. How would one wa-
Unfortunately when the word Xeris- minimum effort” garden. Let’s ex- ter? The table below shows the irri-
cape is used images of hostile cacti plore the three Xeriscape Zones and gation requirements of each plant
and acres and acres of hot, sterile Xeriscape Principle #3 and how I based on my garden conditions (I
gravelscapes comes to mind. It’s an apply them to my garden. know that one gallon of water pene-
image that needs an adjustment. trates ten inches of dry soil in my
The reasoning behind grouping garden).
The word Xeriscape (ZIR-i-scape) plants into Xeriscape Zones is wa-
is derived from the Greek word ter conservation and overall plant (continued on next page)
PLANT FREQUENCY DURATION (using 1 gph emitters)
Agave parryii none-receive sufficient rain (Zone 1) none-receive sufficient rainfall
Acer species - Maple once every 2-3 weeks (Zone 1) 3.5 hrs/rootdepth of 35 inches
Chilopsis linearis - Desert Willow once every 10-15 weeks (Zone 2/3) 3.5 hrs/rootdepth of 35 inches
Dalea pulchra - Bush Dalea once every 12-15 weeks (Zone 3) 2 hrs/rootdepth of 20 inches
Penstemon superbus-Superb Penstemon once every 10-15 weeks (Zone 2/3) 2 hrs/rootcepth of 20 inches
Salvia clevelandii - Chaparral Sage once every 12-15 weeks (Zone 3) 2 hrs/rootdepth of 20 inches
Zinnias once every 7-14 days (Zone 1) 1 hr/rootdepth of 10 inches
Cochise County Cooperative Extension
www.ag.arizona.edu/cochise/mg/
1140 N. Colombo, Sierra Vista, AZ 85635 450 Haskell, Willcox, AZ 85643
(520) 458-8278, Ext. 2141 (520) 384-3594

2. Which set of plants does one Select plants according to their For a list of desert plants
water for? Irrigate for the high horticultural requirements that categorized into Xeriscape Zones
water users and it’s probable that match your site and plant them into point your web browser at
it’s too much water for the drought the proper Xeriscape Zone. Far too http://home.earthlink.net/~melto
tolerant plants, which may decline often I see people choosing plants ncnc/plantlistxeri.htm
due to root rot. Water for the that are not appropriate for the
drought tolerant plants and the high landscape. This begins a long Next time: Have you Probed
water users are sure to die. Either battle of trying to make plants your Garden Lately? – How to
way it’s not a very efficient way to behave the way they want them to. determine when and how long to
irrigate. Guess what? Plants are going to water the garden.
behave the way nature intended
I find it’s important to separate them to. So, choose plants, Cheri Melton
Master Gardener
the Zone 1 and 2 plants. I spent especially for Zones 2 3 that
this summer transplanting Budd- work with Mother Nature and will
leia davidii (Butterfly Bush) from thrive in your landscape!
the Zone 2 garden into the Cuttings
vegetable garden where they are THE XERISCAPE ZONES
now very happy. My main desert ‘N’
garden is a mix of Zone 2 and 3 Zone 1 - For me it contains plants
plants. For areas farthest from the that require regular irrigation Clippings
house I plant strictly with Zone 3 (usually once every 2-6 weeks). As
plants. Interestingly, I’ve talked to a general rule Zone 1 is located
Cochise County Master
people who live in town and the closest to the house (and near a
Gardeners Association will hold
Zone 2 and 3 plants in my garden water spigot) and consists of potted
their November 1 meeting at the
become, respectively, Zone 1 and 2 plants, a small lawn or water
Sierra Vista Library from 5:30
plants in suburban areas due to the feature, annual flowerbeds, and
p.m. - 7:30 p.m. (Note change of
heat loads created by gravelscapes, vegetables and herbs. Drip irri-
time). Guest speaker will be Daryl
concrete walls, roads, and houses gation methods are usually applied
Smith giving an update on the
built so close together you can pass in this area.
Plant Sciences Center at the U of A
the Grey Poupon to your neighbor Zone 2 - In my garden it consists
South Campus. The CCMGA
though the kitchen window. I of drought-resistant plants that
meeting on January 3 will have
happen to live in the “country” so I require deep irrigation (usually
Mark Fredlake with the BLM
don’t have the traditional front once every 12-15 weeks). This is a
“Beaver Project” on the San Pedro
yard. If I did, I would plant my good area to use contouring
as guest speaker.
front yard as a lush Zone 3 garden. techniques such as berms and
Who uses the front yard anymore swales to catch and direct
CCMGA is offering up to
so why water there? Use the Zone rainwater for irrigation or use a
$250 grants to school classes. For
1 and 2 plants in the backyard, drip irrigation system.
details contact Barbara Kuttner at
which is often used and enjoyed by Zone 3 - This is the area where
378-1824. Huachuca Mountain
family and friends. Plant selection drought-tolerant plants that require
Elementary has received the first
would be based on my gardening little or no supplemental irrigation
grant for their garden project.
preferences such as edibles for are used. If you have any natural
feeding family and friends and vegetation and plants in this area
native wildlife plants. on your property—keep it.
Generally this zone is the
Xeriscape Principle #3 is ‘Use furthermost from the house and
Appropriate Plants and Zone the probably least visited. The
Landscape.’ This means doing the emphasis here is to use plants that
Robert E. Call
research through good gardening can survive on rainfall alone. Extension Agent, Horticulture
books, talking with knowledgeable Construct berms and swales to
nursery personnel, Master Garden- catch and direct rainwater for Carolyn Gruenhagen
ers, or Garden Club members. irrigation. Editor
Page 2

3. Garden Basics: IRRIGATION TIPS: · Fittings can leak or come apart
· IMPORTANT! All drip if the water pressure is too high
Popular Irrigation irrigation systems should (use a pressure regulator).
Systems include a filter and pressure · Best used on soil surfaces that
regulator. are level to ensure even flow
· Be sure to run the drip rate.
DRIP EMITTERS: A form of
irrigation system long enough
drip irrigation which applies water
to reach the root zone! If you BUBBLERS: Flood a small area
to the soil at point locations at
run the system for only 15 and the water continues to infiltrate
controlled, low flow rates by means
minutes with a 1 gph (one into the soil after the bubbler has
of drip emitters. Drip emitters
gallon per hour) emitter, only been shut off. The flow rate of
discharge from 0.5 to 4.0 gallons
one quart of water will be bubblers is adjustable from 2.0 to
of water per hour (gph). Many
applied to the soil/plant. 6.0 gallons per minute (gpm),
emitters are pressure compen-
· Ideally, trees should have their resulting in application rates much
sating, applying a nearly constant
own dedicated irrigation line, higher than soil intake rates.
rate of water over a wide range of
and flowers and shrubs should
pressures and elevations.
be on another irrigation line, BUBBLER ADVANTAGES:
due to the different watering · Wets root areas well, good for
DRIP TUBING: Another form of
requirements of each. fruit and ornamental trees
drip irrigation in which water is
(must expand basins regularly
emitted at equally spaced points (6
SOAKER HOSE: A porous hose to cover the root zone).
to 60 inches apart) along a tube.
that allows water to seep out along · Bubblers are easy to clean, not
The tubing is semi-rigid with
the entire length of the hose. prone to clogging.
emitters built right into the tubing.
Depending on the type of soaker
These emitters can be pressure
hose, operating pressures are from DISADVANTAGES:
compensating. Drip tubing dis-
5 to 20 psi (pounds per square · Best used on soil surfaces that
charge is expressed in gallons per are level.
inch). Soaker hoses ooze water at
minute (gpm) per 100 ft of · Are only applicable in areas
a rate of 0.6 to 0.8 gallons per
tubing. where basins can be
hour (gph) per foot. It is a good
idea to install a filter and pressure constructed to contain the
ADVANTAGES OF DRIP regulator on a soaker hose system water.
IRRIGATION:
(choose one that will keep the
· Plants may be watered at any
pressure below 10 psi). SPRINKLERS: Commonly used
time of the day. Since water is
for turfgrass applications.
applied at the base of the plant
ADVANTAGES OF SOAKER Selection of sprinkler type depends
and does not get on the leaves,
HOSES: on size and shape of area being
there is less chance of
· Sturdy, easy to hook up, irrigated, and the flow rate and
damage/disease to the foliage
movable, flexible (can be pressure of the water supply.
from too much moisture.
snaked around existing plants - Water pressure higher than what is
· Irrigation is at ground level,
great for vegetable gardens, recommended for the sprinkler
right over the roots, so very
annual flower beds, plant tends to make small water drops,
little water is lost to
groupings, and trees). which are subject to evaporation
evaporation.
· Can either be laid on top of the and drift in windy conditions. Low
soil or buried in the soil. water pressure decreases the radius
DISADVANTAGES:
· Irrigation is at ground level so of “throw” and does not break up
· Emitters can clog, especially
little water is lost to the water stream properly, causing
since our water is “hard,”
evaporation. poor uniformity of application.
(contains lots of minerals).
Putting a filter on your
DISADVANTAGES: (Continued on next page)
irrigation system will help.
· Hoses can clog especially with
· System needs to be inspected Be
hard, mineralized water source
routinely for problems such as
(using a filter will help).
leaks and clogged emitters. F or t H u ac h u ca
T e l e p h o n e : (5 2 0 ) 5 3 8 -S A V E
Page 3

4. ADVANTAGE OF DISADVANTAGES: meat has not fully matured and is
SPRINKLER IRRIGATION: · None! Harvesting rainwater is the cause of the stick-tight
· Most effective way to water a “win-win” situation! condition. Harvest is then a matter
large grassy areas. of picking up nuts off of the ground
FOR MORE INFORMATION: before wildlife does! Com-
DISADVANTAGES: Harvesting Rainwater for mercially, mechanical shakers are
· High water loss due to Landscape Use by Patricia H. used to shake nuts to the ground
evaporation. Water is thrown Waterfall and then they are swept up from
out into the air instead of http://ag.arizona.edu/pubs/water/ the ground mechanically. Nuts
applied directly to the soil. az1052/ need to be separated from the
· On windy days, sprinkler water High Desert Gardening - Cochise shucks if they are not already. This
can be blown out of the County Master Gardeners Website is done by hand if only a few trees
watering pattern, resulting in http://www.ag.arizona.edu/ are involved. Commercially there
uneven application of water cochise/mg/ are hulling machines that are a set
and excessive evaporation. of brushes that rub the husks off,
Ginger Maxey producing cleaned nuts. The final
Master Gardener/Ft. Huachuca Water
DID YOU KNOW? Garden Conservation Educator
step is to crack the shell and just
hoses deliver water at a rate of have the meats for eating. This is
between 5-7 gallons per minute! done by hand, one nut at a time, or
That’s a lot of water!!!! with the aid of one of several nut
crackers. On a larger scale, nuts
RAINWATERING are placed in a machine that will
HARVESTING: The capture, singulate them and mechanically
diversion, and storage of rainwater crack them. The meats are removed
for plant irrigation and other uses. by hand.
Water can be directed to earth Call’s Classic To determine if you had a good
berms and swales, or into nut year, collect a sample of your
barrel/cistern systems and stored Comments nuts. Clean off all of the shucks
for use during dry periods. and weigh it. Crack and shall all
I have received many questions the nuts and weigh the remaining
ADVANTAGES OF about pecan trees and when to meats. Divide the meat weight by
RAINWATER HARVESTING: harvest the nuts. Pecan nuts are the nut weight to get a percentage.
· Provides “free” water and ready to eat when the shuck splits. A good nut to meat percentage is
reduces dependence on ground The shuck is the husk or fleshy between 50 - 55%. Anything over
water. material around each individual 55% is an excellent yield. If this
· Sloping ground enhances the nut. The nut consists of the shell was not accomplished, culture
effectiveness of using berms and the meat. Commercial harvest practices such as watering
and swales. in Cochise County usually begins schedules and fertilization should
· Reduces off-site flooding and around Thanksgiving. When the be improved.
erosion by holding rainwater nut meat has filled the shell the
on the site. husk will start to split, slowly dry, Also on the subject of trees this
· Rainwater is a clean, salt-free and open. Many nuts will drop to month, now is NOT the time to
source of water for plants – it the ground on their own. After prune fruit and shade trees. Plants
also contains dissolved several hard freezes, nuts will are preparing to go into winter on
atmospheric nitrogen, a really start to fall to the ground. the high deserts. Pruning is a
fertilizer that is lacking in our Sometimes the shuck does not dwarfing, stimulating, and stressful
native soils! separate from the nut thus event. Trees and shrubs are moving
producing what is called a
“stick-tight.” Many times the nut (continued on next page)
Issued in furtherance of Cooperative Extension work, acts of May 8 and June 30, 1914, in cooperation with the United States Department of Agriculture, James A. Christenson,
Director, Cooperative Extension, College of Agriculture and Life Sciences, The University of Arizona and Arizona Counties cooperating. The University of Arizona College of
Agriculture and Life Sciences is an equal opportunity employer authorized to provide research, educational information and other services only to individuals and institutions
that function without regard to sex, race, religion, color, national origin, age, Vietnam Era Veteran’s status, or disability.
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.
Page 4

5. compounds from the leaves and
branches and storing carbohydrates 7KH 9LUWXDO *DUGHQHU³ With the advent of weather
satellites, sophisticated sensors,
in the trunks and roots. If pruning (O 1LxR /D 1LxD /D 1DGD and more powerful computers,
is done now, buds that are going weather scientists have discovered
dormant are stimulated and might many more oscillations besides the
begin to grow using energy and About this time every year I ENSO. Our weather in western
other resources that are normally begin wondering what the winter
North America is also affected by
stored to survive winter and the will be like. Will it be warm or
an oscillation in the northern
spring push of rapid growth and cool? Wet or dry? In Southeastern
Pacific called the Pacific Decadal
development of leaves and shoots. Arizona we have been lucky for the
Oscillation (PDO), an Arctic
Next spring’s growth takes a lot of last few years to have fairly warm
Oscillation (AO), and even a North
energy and if used up in the fall winters and that has caused a lot of
Atlantic Oscillation (NAO). At this
and winter because of pruning folks to buy plants that might be a
point, however, the scientists do
stimulation can cause plants to little tender for the some of the
not fully understand the cause and
become stressed and even die if winters we have historically had
here. I thought it might be effect relationships between these
winter conditions are severe. All of oscillations and our weather and
this growth needs to occur in the interesting to find out what the
weather gurus have to predict they are not able to reliably predict
spring before photosynthesis can when they occur.
begin anew in deciduous plants. about the winter this year so I
Even evergreens’ growing activity surfed to the National Oceanic and
Atmospheric Administration's Scientists at the Climate
in the winter slows and in some Prediction Center sifted through
cases stops. Stimulating new (NOAA) Climate Prediction Center
at www.cpc.necp.noaa.gov/ historical weather data to filter out
growth is just opposite of what the
products/winter_outlook/. data for winters where ENSO and
plant needs to have happen to
PDO/AO conditions have been
survive the winter season.
Over the last couple of decades equivalent to those we are
Prune most fruit and shade trees
we have learned a lot of new things experiencing this year. After look-
just before bud swell occurs in late
about global weather cycles. ing at all the evidence, they are
winter or early spring between
Unless you have been hermetically predicting a winter for North
February and April. With many
sealed in a cave you have probably America that is warmer than the
flowering ornamental plants the
recommendation is to prune after heard about the El Niño/Southern long term average but generally
flowering occurs. If you have a Oscillation (ENSO) phenomenon in cooler than the last three years.
question on a specific plants the South Pacific and its sister La Specifically for Arizona, their
pruning requirement contact the Niña that have such a big effect on prediction indicates that the
Extension Office in Sierra Vista or global weather, causing droughts in northern two-thirds of the state will
(continued on back page)
Willcox. Africa and floods in Peru. An El
Source: November 1994 Cochise Niño condition occurs when a huge
County Master Gardener Newsletter pool of warm ocean water migrates
eastward across the central Pacific 4UKSHKX
Robert E. Call
Agriculture Agent, Horticulture
until it bumps into South America
around December (hence the name
which refers to the Christ Child in
8KSOTJKXY
Spanish). When a huge pool of This is a good time to install
cool water moves eastward across a drip system
the Pacific we have the opposite of Replace summer mulch with
an El Niño condition referred to as fresh mulch
La Niña. After several years of Start a winter herb garden
extremes, this year we have an Protect plants from frost (The
ENSO neutral condition, sort of a bulletin Frost and Frost Pro-
“La Nada” year. tection is available from the
Cooperative Extension offices)
Page 5

6. ARIZONA COOPERATIVE EXTENSION
U.S. DEPARTMENT OF AGRICULTURE PRSRT STD
Cochise County POSTAGE FEES PAID
450 S. Haskell Avenue USDA
Willcox, AZ 85643-2790
OFFICIAL BUSINESS PERMIT NO. G268
PENALTY FOR PRIVATE USE $300
Address Correction Requested
High Desert Gardening Landscaping Conference
February 15 16, 2001
average 2-4°F cooler than last year Precipitation this winter is pre- Scholarships Offered
while the southern one-third of the dicted to be near normal. If the pre-
state (including Cochise County) diction is correct we should get The Cochise County Master Gar-
will average only 0-2°F cooler than roughly the same amount of rain deners Association (CCMGA) is
last year. Of course you should re- this winter as we normally get dur- awarding up to five full scholar-
member that the prediction only ing the summer monsoons, about 7 ships to the 2001 High Desert Gar-
deals in averages. It says nothing to 8 inches in valley areas. This dening Landscaping Conference
about specific weather events such will be a pleasant change from last to be held at the Lakeside Activity
as the severe cold snap that low- year. Of course if October is any Centre located on Ft. Huachuca,
ered temperatures to 6°F in Sierra indication, we might get even more. AZ, on February 15 and 16, 2001.
Vista on the 8th of December Applicants are invited to submit an
1978. When buying long-lived Sometime next spring, take a essay on one of the following
plants such as trees, remember that look back at the winter and see topics:
even though we haven't had very how good these forecasts were. I'm Gardening for food production
Landscaping with native plants
cold temperatures for the past few willing to bet there will be some
Environmental stewardship
years, the law of averages will surprises.
catch up with us one of these
For details please contact the Co-
years. Play it safe and buy only Until next time. Happy surfing.
operative Extension Office in Si-
plants that are rated as cold hardy
Gary A. Gruenhagen, Master Gardener erra Vista or check the web site.
for your area.
gruenha@sinosa.com