Landscape Water Conservation...
Xeriscape TM
Douglas F. Welsh, Extension Horticulturist
William C. Welch, Extension Landscape Horticulturist
Richard L. Duble, Extension Turfgrass Specialist (retired)
Texas Agricultural Extension Service
An adequate supply of high quality water has become a critical issue for
the future prosperity of Texas. Booming populations have increased the demand
on the state's already limited supply of high quality water. In addition,
seasonal fluctuations in rainfall and periodic droughts have created a
feast-to-famine cycle in Texas.
In urban areas of Texas about 25 percent of the water supply is used for
landscape and garden watering. Much of this water is used to maintain
traditionally high water-demanding landscapes, or it is simply applied
inefficiently.
In an attempt to reduce the excessive water use, the Texas Agricultural
Extension Service is educating Texans in Xeriscape landscaping, quality
landscaping that conserves water and protects the environment. This concept is
a first-of-a-kind, comprehensive approach to landscaping for water
conservation. Traditional landscapes may incorporate one or two principles of
water conservation, but they do not utilize the entire concept to reduce
landscape water use effectively.
Xeriscape landscaping incorporates seven basic principles which lead to
saving water:
- Planning and design
- Soil analysis
- Practical turf areas
- Appropriate plant selection
- Efficient irrigation
- Use of mulches
- Appropriate maintenance
By incorporating these seven principles, you can help preserve our most
precious natural resource-water.
Xeriscape landscapes need not be cactus and rock gardens. They can be
green, cool landscapes full of beautiful plants maintained with
water-efficient practices. The same green Texas-style landscape which we are
accustomed to can be achieved and still conserve water.
Start With a Plan
Creating a water-efficient landscape begins with a well-thought-out
landscape design. Sketch your yard with locations of existing structures,
trees, shrubs and grass areas. Then consider the landscape budget, appearance,
function, maintenance and water requirements. Local landscape architects,
designers, nurserymen and county Extension agents can help in this decision
making. Implementing your landscape design can be done gradually over several
years.
Soil Analysis and Preparation
To increase plant health and conserve water, add organic matter to the soil
of shrub and flower bed areas. This increases the soil's ability to absorb and
store water in a form available to the plant. As a rule-of-thumb, till in 4 to
6 inches of organic material such as shredded pine bark, peat and rice hulls.
For trees, however, incorporating organic matter is not necessary; for large
turfgrass areas, it is not economically feasible.
Plant Selection
Select trees, shrubs and groundcovers based on their adaptability to your
region's soil and climate. Texas is blessed with an abundance of beautiful
native plants which are naturally adapted to the region. Most have lower water
demands, fewer pest problems and less fertilizer needs than many nonadapted,
exotic plants brought into Texas landscapes.
Through the support of the nursery industry, native Texas plants are
becoming more available in retail nurseries and garden centers. Combining
Texas natives with well-adapted exotic plants is a key to a beautiful,
interesting landscape which conserves water. Refer to the tables in this
publications, and check with your local nursery or county Extension agent for
recommendations on adapted landscape plants for your area.
- Outstanding Landscape Plants for Texas Xeriscapes
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Grasses
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Vines and Groundcovers
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Perennials
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Shrubs
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Trees
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Water-Saving Native Plants
Grass Selection
When considering a landscape's water requirement, it is important to note
that turf grasses require more frequent watering and maintenance than most
other landscape plants. Carefully select grass according to its intended use,
planting location and maintenance requirements.
St. Augustine grass and Bermuda grass are most often used for lawns in
Texas. Zoysia grass, buffalo grass and centipede grass are used less often but
offer much promise for landscape water conservation.
Grasses available for use in Texas lawns vary significantly in water
requirements. Planting the lowest water use turf grass adapted to the region
is an effective way to reduce landscape irrigation requirements.
Achieving a significant reduction in water consumption and landscape
maintenance may also involve reducing the size of water-sensitive lawns
through the use of patios, decks, shrub beds and groundcovers.
Also, when designing or evaluating turf grass areas in the landscape,
consider the ease or difficulty in watering the proposed area. Long narrow
areas and small odd-shaped areas are difficult for any irrigation equipment to
efficiently water. Try to eliminate long, narrow areas and maintain more
blocky, square areas.
Landscape Maintenance
An added benefit of Xeriscape landscapes is less maintenance. A
well-designed landscape can decrease maintenance by as much as 50 percent
through reduced mowing; once-a-year mulching; elimination of weak, unadapted
plants; and more efficient watering techniques.
Watering
Of the tremendous amounts of water applied to lawns and gardens, much of it
is never absorbed by the plants and put to use. Some water is lost to runoff
by being applied too rapidly, and some water evaporates from exposed,
unmulched soil; but, the greatest waste of water is applying too much too
often.
In addition to over watering the plant, excess irrigation can leach
nutrients deep into the soil away from plant roots, increasing the chances of
polluting groundwater. Similarly, runoff caused by excess irrigation can carry
polluting fertilizers and pesticides to streams and lakes. The waste or
pollution of high quality water through inefficient irrigation practices can
be eliminated through proper watering techniques.
Lawns
Most lawns receive twice as much water as they require for a healthy
appearance. The key to watering lawns is to apply the water infrequently, yet
thoroughly. This creates a deep, well-rooted lawn that efficiently uses water
stored in the soil.
To know when to water the lawn, simply observe the grass. Wilting and
discoloration are signs of water stress. At the first sign of wilting, you
have 24 to 48 hours to water before serious injury occurs. Apply 1 inch of
water to the lawn as rapidly as possible without runoff.
Watering only when needed and watering thoroughly produces a deep-rooted
lawn which is more water efficient and drought enduring.
Trees and Shrubs
All trees and shrubs need more frequent watering from planting time until
becoming well rooted, which may take two growing seasons. Once established,
plants can then be weaned to tolerate less frequent watering. Proper weaning
develops deep roots and makes the plants more drought enduring.
As with lawns, water established trees, shrubs and groundcovers
infrequently, yet thoroughly. In the absence of rain, most trees and shrubs
benefit from a once-a-month thorough watering during the growing season.
Remember, normal lawn watering is not a substitute for thorough tree and shrub
watering.
The feeding root system of a tree or shrub is located within the top 12
inches of the soil and at the "dripline" of the plant. The dripline is the
area directly below the outermost reaches of the branches. Apply water and
fertilizer just inside and a little beyond the dripline, not at the trunk.
Simply lay a slowly running hose on the ground and move it around the dripline
as each area becomes saturated to a depth of 8 to 10 inches. For large trees,
this watering technique may take several hours.
Irrigation Systems
The goal of any irrigation system is to give plants a sufficient amount of
water without waste. By zoning an irrigation system, grass areas can be
watered separately and more frequently than groundcovers, shrubs and trees.
Both sprinkler and drip irrigation can be incorporated to achieve water
conservation in the landscape.
Sprinkler Irrigation
Sprinkler irrigation is the most commonly used method of landscape watering.
The two most common types of sprinkler irrigation systems are the hose-end
sprinkler and the permanent underground system. Even though a permanent
sprinkler system can be more water efficient than a hose-end sprinkler, both
systems require little maintenance and apply large volumes of water in a short
time.
If you have a permanent sprinkler system, make sure the sprinkler heads are
adjusted properly to avoid watering sidewalks and driveways. Also, a properly
adjusted sprinkler head sprays large droplets of water instead of a fog of
fine mist which is more susceptible to evaporation and wind drift.
With either hose-end sprinklers or permanent systems, water between late
evening and mid-morning to avoid excessive waste through evaporation.
Drip Irrigation
Drip irrigation offers increased watering efficiency and plant performance
when compared to sprinkler irrigation. In areas of the state with poor water
quality (i.e., high salt content), drip irrigation also allows safer use of
"salty water" in the landscape and garden.
Drip irrigation slowly applies water to soil. The water flows under low
pressure through emitters, bubblers or spray heads placed at each plant. Water
applied by drip irrigation has little chance of waste through evaporation or
runoff.
Seeking professional irrigation advice and experimenting with available
drip irrigation products in small sections of the landscape are the best ways
to become familiar with the many benefits of this watering technique.
Mulching Conserves Moisture
Mulch is a layer of nonliving material covering the soil surface around
plants. Mulches can be organic materials such as pine bark, compost and
woodchips; or inorganic materials, such as lava rock, limestone or permeable
plastic, not sheet plastic.
Use a mulch wherever possible. A good mulch conserves water by
significantly reducing moisture evaporation from the soil. Mulch also reduces
weed populations, prevents soil compaction and keeps soil temperatures more
moderate.
Proper Mowing and Fertilizing Conserves Water
Mowing grass at the proper height conserves water. Mow St. Augustine grass
and buffalo grass at 3 inches; for Bermuda grass mow at 1 inch; for centipede
grass and Zoysia grass mow at 2 inches.
Applying fertilizer to the lawn at the proper time and in the proper amount
can save time, effort and money through reduced mowing and watering.
Fertilizers also can be a major source of pollution of streams and groundwater
if excessive amounts are applied.
Fertilize the lawn once in the spring and again in the fall to produce a
beautiful turf without excess growth which demands frequent watering. Use a
slow-release form of nitrogen in the spring application and a quick-release
form in the fall. Apply only 1 pound of actual nitrogen fertilizer per 1,000
square feet of lawn at one time. By using this fertilizer schedule, no other
fertilizer is needed to maintain most shrubs and trees in the lawn area.
Other Cultural Practices To Save Water
Other cultural practices that add to the efficient use of water by plants
are periodic checks of the irrigation system, properly timed insect and
disease control and elimination of water-demanding weeds.
Water Conservation Commitment
For each person in Texas, water must always be a vital concern. Water is a
limited and fragile resource. The water used to irrigate landscapes is
considered a luxury use of water by many people. Nonessential use of water
implies a special responsibility to efficiently use the resource and to
protect its quality.
Water conservation in the landscape does not mean planting a harsh cactus
and rock garden. It means common sense landscaping to protect water quality
and quantity. It also means following the principles of water conservation to
insure continued prosperity for the residents and businesses of Texas.
By following these guidelines and tips, you can proudly create your own
Xeriscape landscape.
Xeriscape Landscaping
Xeriscape landscaping, quality landscaping that conserves water and
protects the environment, is the most exciting concept to hit the landscape
industry in decades. The term Xeriscape was coined in Denver, Colorado in
1978. Whether called Xeriscape, water-wise or water-smart landscaping,
landscape and water industry professionals throughout the nation have embraced
landscape water conservation through education.
Texas has more than 20 educational projects currently active. Demonstration
gardens and tours, seminars, television programs and design contests are just
a few of the methods used to make the Xeriscape concept familiar throughout
Texas and the nation.
The seven principles of Xeriscape landscaping are not new; they have been
practiced in the landscape industry for decades. The concept of combining all
seven guidelines into one effort toward landscape water conservation is what
makes Xeriscape landscaping unique. The principles are given below:
| 1. Planning and design is the foundation of any
water-wise landscape. |
 |
| 2. Soil analysis will determine whether soil improvement is
needed for better water absorption and improved water-holding capacity.
|
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| 3. Practical turf areas suggests that turfgrasses be used as a
planned element in the landscape. Avoid impractical turf use, such as
long, narrow areas. |
 |
| 4. Appropriate plant selection keeps the landscape more in tune
with the natural environment. Both native and exotic plants make up the
huge variety of plants available for Xeriscape landscaping. |
 |
| 5. By simply using efficient irrigation, you can instantly save
30 to 50 percent on your water bill. |
 |
| 6. Use mulches in flower and shrub beds to prevent water loss
from the soil through evaporation and to increase water penetration during
irrigations. |
 |
| 7. Appropriate maintenance preserves the beauty of the
Xeriscape landscape plus saves water. Pruning, weeding, proper
fertilization, pest control and irrigation system adjustments all conserve
water. |
 |
. . . seven simple steps to landscape water conservation. Join the
Xeriscape movement. Check with your local water department or county Extension
agent for more information.
Xeriscape and the Xeriscape logo are trademarks of the
Denver Water Department.
Hypertext markup by Gretchen Eagle and Dan Lineberger.
http://aggie-horticulture.tamu.edu/extension/xeriscape/xeriscape.html
Revised 26 October 2000
Houston Xeriscaping
