The following blog post has been adapted from a piece Davey contributed to the Association of Professional Landscape Designers' (APLD) Spring 2015 issue of The Designer magazine.
Persistent drought conditions across the southwestern U.S. illustrate the need for landscape designs that can endure harsh drying trends.
The challenge lies in meeting low-water demands without sacrificing beauty or functionality.
By choosing the right tree, you can create a landscape with all the benefits trees have to offer—even for clients located in hot, dry climates.
Xeriscape your Landscape
A growing trend in the western U.S. and other dry areas is xeriscaping, a landscape water conservation concept that originated in Colorado.
The term ‘xeriscape’ comes from xeros, the Greek word for ‘dry,’ according to the University of Nevada, Las Vegas. The concept has spread throughout the west to use water-efficient landscape designs to eliminate irrigation.
Xeriscape methods range from replacing whole sections of turf with permeable gravel or mulch to carefully selecting shrubs, trees and other plants for rain gardens in dry areas. It’s a practice that is becoming widely accepted by government entities and homeowners associations.
Trees with Low-Water Needs
Not all trees need buckets of rain each year to grow tall, offer shade and color the landscape.
- The Kentucky coffee tree grows naturally in the east but lives as far southwest as Oklahoma and Texas. It can tolerate drought and adapts well to plant hardiness zones ranging from 3 to 8 as defined by the U.S. Department of Agriculture. This species can potentially grow well in New Mexico, Colorado, California and Oregon—all states hit hard by the ongoing drought, according to the National Oceanic and Atmospheric Association.
- Western hackberry is native to the western U.S. and grows to about 25 feet, can withstand full sun and low water. The Boxelder, Acer negundo, also native to the west grows as high as 40 feet and is a fast-growing shade tree. The Deodar Cedar tree, Cedrus deodara, is an evergreen native to the western Himalayas that grows well in warm climates and can reach heights of 130 feet.
- Stout deciduous and conifer trees aren’t the only option for arid landscapes. There are many smaller, ornamental trees and shrubs that prove quite tolerant to drought while offering aesthetic benefits.
- The blue mist spirea, a native Colorado plant suited for dry conditions, grows to about 4 feet tall and features blue-violet flowers that bloom from July to September. It grows well in full sun and is drought tolerant.
- Fernbush grows to about 6 feet tall, withstands full sun and needs little water.
- Pineapple guava is native to Brazil and Argentina and features exotic, pink flowers. It is drought tolerant once established and works well as a hedgerow or small tree up to 15 feet tall.
Where to Consider Low-Water Trees
In Colorado, finding plants that will thrive in the state’s arid climate without ample irrigation requires careful selection, according to the Colorado State University Extension.
The Colorado State extension advises examining the site’s soil, drainage and sun exposure prior to planting. Some plants can tolerate less water, but they may not grow as well in the low-oxygen soils found at higher altitudes.
The Scottsdale Water Resources Department and Scottsdale Xeriscape Garden at Chaparral Park in Arizona educate residents about the value of planting hardy, native trees and shrubs that are well adapted to desert life.
Low-Water vs. No-Water
No tree or shrub can survive without water even though many can thrive in regions where there is little natural moisture.
Many cities in New Mexico average just 8 inches of precipitation or less each year. Some tree and shrub species will require some additional irrigation, if available, or you will need to carefully consider their location—such as in a rain garden where they will benefit from storm runoff from down spouts.
The University of Nevada, Las Vegas, also recommends contouring the landscape plan in such desert regions to collect natural rainfall and funnel it towards landscape plants.
And, it’s important to recognize that all trees need adequate water during the first two to three years after they’ve been planted.