The
term Xeriscape was created by Nancy Leavitt in conjunction with the
Denver Water Department in 1981. The goal then and now is to develop
sensible gardening methods which ensure water conservation. The word,
Xeriscape, comes from the Greek word "xeros", meaning dry. This in
combination with the word, landscape, gives us Xeriscape. Xeriscape
is very beneficial to the environment in the arid west helping both
nature and man.
The
word Xeriscape is pronounced like zeer-i-scape. Unfortunately early
and misguided attempts at water conservation incorporated too much
"rock mulch".
Those
early efforts represented "zeroscapes". Xeriscapes are entirely different.
Today,
many people cannot tell a Xeriscape garden from a more traditional
planting without close inspection. There are seven commonsense steps
to water wise gardening that can be applied to new spaces or to retrofit
old gardens.
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Seven
Steps to Xeriscape
Planning
and Design
Good
planning and design may seem obvious but it is the key to final success.
With proper advance planning and a drawn design, the other six Xeriscape
steps will be easier to accomplish.
Each
area around a dwelling or other structure exists in or creates its
own microclimate. The existing location of outside water sources may
pose a distance problem and possibly limit the finished design. Drawing
a sketch of the site will demonstrate some of these differences. The
location for plantings is critical to their successful growth and
survival. If done to scale, the drawing will also allow basic calculations
for the size and quantity of items needed for the new Xeriscape garden.
The
north and east sides of a building will receive less sunlight, therefore,
the soil will be cooler and probably hold more moisture throughout
the year. South and west exposures will be warmer and drier.
Prevailing
winds will affect the garden site as will shade from nearby large
trees. By mapping the total site in the planning stage, these unique
aspects or microclimates will be seen and can be studied for the best
Xeriscape treatments.
Ultimately,
plants requiring more moisture or cooler environments will be grown
together and those with very low water needs that can tolerate full
sun will be grouped together. Plants with similar needs should be
grouped together in the best location possible. Also, considerations
for plant heights, colors, and blooming periods are best selected
based on location.
Lawn
and/or turf areas should be planned according to use. Will the grass
be used for a play area or for beautification or as a buffer between
residences or other view distractions?
Another
thing to consider is slope. Sloping areas can be very difficult to
mow and will function better if terraced and planted to perennial
ground covers.
Advance
total planning ensures saving time and money. Key planning concerns
include the following: water source, slope, use, space requirements
based on microclimates, width and height of plantings, uniformity
of water requirements, color and blooming periods.
Soil
Improvement
Most
Colorado soils are predominately sand and clay minerals. In their
natural state, these soils usually contain little organic matter or
humus. Sandy soils do not hold much water or many nutrients for plants.
Clay soils become hard and compacted making it difficult for water,
air, and plant roots to penetrate. For lawns and gardens to thrive,
the natural soil needs to be amended with organic matter like aged
manure or compost.
Amending
the soil is the most important step when the actual physical work
begins on the Xeriscape garden. There are many local companies providing
aged manure or well composted wood chip and manure products. Composting
organic matter creates weed-free humus and gives the finished soil
product a light texture. Improving the soil quality allows plants
to receive water, air, and nutrients more readily.
Limit
Turf Areas
The
greatest use of outdoor watering is concentrated on lawns. The best
way to reduce this use and conserve water is by limiting lawn areas
or by planning them for specific use. Limiting the size of lawns also
results in time and money savings. Lawns require regular maintenance
and often rely heavily on expensive fertilizer and pesticide applications.
Most
Colorado lawns are planted to Kentucky blue grass. By determining
the actual use for the lawn area in advance, fewer high maintenance
areas can be established. In general, when used correctly, grasses
offer some of the most versatile Xeriscape plantings.
There
are many species available that require much less water than blue
or rye grasses. Children’s play areas that require tough turf can
be established to sod turf-type tall fescue, or native buffalo or
grama grass.
Tall
fescue is drought tolerant and when kept mowed still provides that
"bare foot grass" feeling. A planting of smooth brome and tall fescue
can be used as a weed free low maintenance barrier or screen if left
to grow naturally. Many individual bunch grasses provide excellent
color and contrast within flowerbeds.
Use
Plants With Low Water Requirements
There
are long lists of plants that have proven records for Xeriscape gardening.
The problem with plant selection is not finding enough correct plants
but actually limiting choices based on space and budget considerations.
Again,
the basic plan will become the guide for plant selection by location,
height, color, and blooming season. Most people collect ideas from
existing gardens for their final plan. Visiting established Xeriscape
demonstration gardens in the Front Range area is an excellent way
to make choices. Many water departments have promoted Xeriscape gardens
at their facilities and location lists are available. Most plantings
in these gardens have identification tags on plants to help visitors
recognize species.
Use
Mulch
After
improving the soil and making proper plant selections, mulch is the
next most important step in the establishment of a well functioning
garden.
Mulches
accomplish several things in a Xeriscape planting. Mulches provide
temporary cover until plants mature and "fill in" open spaces. Also,
acting like a blanket over the soil, mulch reduces water evaporation
from the soil surface. Because the mulch blocks sunlight, it prevents
weed growth but still allows air and water circulation.
Technically,
almost anything can be used as mulch. Straw, newspapers and rocks
have all been utilized as mulch. A popular method for applying mulch
today incorporates the use of landscape fabric. (This is not
black plastic.) Landscape fabric looks and feels much like felt. This
fabric is placed directly over the soil and then topped with shredded
bark, wood chips, small rocks or other aesthetically pleasing material.
Landscape fabric "breathes", allowing air and water to circulate.
Effective
Irrigation
Once
the garden and lawn is planted, most maintenance time, energy, and
money will be spent on watering. Most, but not all, irrigation can
be reduced with the initial selection of drought tolerant plants and
grasses and by clumping plants with greater or less water needs. Create
watering zones by plant needs and location.
Over
watering carries yard chemicals like fertilizers and pesticides into
street gutters and is becoming a significant cause of water pollution.
Drip irrigation systems help avoid this, since the emitters can place
water right at the root zone. These systems are excellent for shrubs
and trees. Buried porous hose and/or short umbrella or bubble sprinklers
place large droplets near plants and do not lose water through evaporation
as badly as fine spray sprinklers. Most garden and nursery centers
have a wide choice of water conserving systems. Many area Soil Conservation
Districts also sell drip irrigation supplies.
Appropriate
Maintenance
As
with so many long-term projects, the yard and garden around residences
require regular upkeep. Weeding, watering, mowing, pruning, fertilizing
and pest control will still be necessary in the Xeriscape setting.
In
summary: weeding, watering and mowing can best be controlled by limiting
turf grass area, mulching and selection of lower growing turf grasses.
Pruning labor is relative to the numbers and types of woody shrubs
or trees planted.
Insect
pests or plant diseases should pose fewer problems in the Xeriscape
garden. By selecting hardy, native species, part of the general disease
and pest problem will be eliminated. Another way to help control pests
is to allow adequate space between plants for air circulation and
penetration of sunlight.
Sometimes
the best intentions and planning still fail to keep disease or pests
out of the garden and lawn. For those wishing to avoid the use of
manmade chemicals there are many natural alternatives available at
garden centers or through publications for gardeners.
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Additional
Information
Denver
Water
1600
West 12th Avenue
Denver,
CO 80254
(303)
628-6000
www.denverwater.org
Xeriscape
Colorado!, Inc.
www.xeriscape.org
Plant
Talk Colorado
1-888-666-3063
http://www.ext.colostate.edu/ptlk/index.html
Colorado
State University Extension – fact sheets
4.702
Trickle Irrigation for the Home Garden
7.212
Composting Yard Waste
7.228
Xeriscaping: Creative Landscaping
7.229
Xeriscaping: Trees and Shrubs
7.231
Xeriscaping: Garden Flowers
7.232
Xeriscaping: Turf and Ornamental Grasses
7.234
Xeriscaping: Retrofit Your Yard
Denver
Botanic Gardens
909
York Street
Denver,
CO 80206-3799
(303)
331-4000
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Xeriscape
is a registered trademark of Denver Water, Denver, CO and is used
here with permission.