Maintaining home landscapes can be difficult in a year with normal precipitation, but Colorado’s multi-year shortfall of snow and rain, coupled with yet another dry winter, may make this spring and summer particularly challenging.
An appropriate and healthy residential landscape can add value to property and improve air and water quality. In addition, a sizable percentage of Colorado’s Front Range water is used for landscapes, making yards and gardens an ideal place for voluntary water conservation measures and can provide an option for water providers to reduce water demand by imposing a variety of restrictions.
"People who are installing a new landscape or retrofitting an existing one have an expanded opportunity to use xeriscape plants and principals to build an attractive yet water-efficient landscape," said Jim Klett, Colorado State University Cooperative Extension horticulturalist. "But additional strategies provide homeowners with tools to conserve water, and spring is an ideal time of year to start."
Klett says that landscapes become more water efficient when design and technical principals are combined.
During a drought, trees should receive the highest priority for watering because they take years to replace. Newly transplanted trees are the top priority. Young trees, which usually measure 1 to 7 inches in diameter, have a limited root system and need supplemental water even during normal precipitation years. Trees growing in a restricted root zone, such as those in strips between sidewalks and streets, also need higher priority.
Trees use water best when the water is allowed to soak slowly into the soil to a depth of about 12 inches. Use a deep-root fork or needle, soaker hose or soft spray wand, or apply water to many locations through a drip line. To calculate how much water a tree needs, apply 10 gallons of water per inch of the tree’s knee-high diameter. During the fall and winter, water trees one to two times a month when no lawn watering is allowed. In the spring and summer when lawns are being watered, water trees every other week or weekly, depending upon the size of the tree, weather, watering restrictions, temperature and soil conditions.
Finally, don’t fertilize trees that are stressed because fertilizer salts may burn roots.
Adding organic matter to soil before planting trees and shrubs helps to retain moisture and essential nutrients, and enlarging mulch beds under trees and shrubs helps soil retain moisture and reduces the amount of grass in a lawn, which can reduce water consumption. Use organic mulch, such as woodchips, bark, dried leaves or evergreen needles. Mulch under trees, shrubs or perennials can reduce water use by as much as 50 percent compared to the same area if planted in bluegrass. A 4-inch-deep mulch also reduces heat stress on plants by regulating soil temperature.
Flower gardens need extra preparation before planting to optimize water conservation. First, prepare the soil with 1 to 2 inches of organic matter or compost, and till the ground about 12 inches deep.
Select plants and flowers for landscapes by their specific water and sunlight needs, and use soaker hoses or drip irrigation in flower beds. Hand-watering also maximizes delivery of water to soil and roots.
Vegetable gardens also need adequate water. To help reduce vegetable garden water demands, add organic matter to the soil, use drip irrigation or trickle or soaker hoses, check soil moisture before applying water to be sure that additional water is needed and mulch between plants to minimize evaporation.
For more information about landscape care during a drought, call the local Colorado State University Cooperative Extension office, usually listed under the county government section of the local phone book, or visit http://www.ext.colostate.edu/PUBS/GARDEN/07240.html.