By Warren Tenney
It’s the time of year when many homeowners are tired of the glare from their windows and are thinking about adding more shade to their yards. The beautiful combination of cactus, succulents and desert-adapted flowering shrubs are unique to our communities, but trees give height and width to a landscape. In the desert summer, trees also help to cool a home’s windows and walls and keep its air conditioner from overworking. We asked AMWUA cities’ conservation professionals about a few of their favorite water-efficient shade trees. These trees lose all or most of their leaves in the winter so they are best planted on the south and west sides of your home. That will give you maximum shade in the summer and allow light and warmth into your home and yard in the winter.
- Chinese Pistache (Pistacia chinensis) This large tree is always showing off. Its green canopy turns bright yellow and red in December and then drops its leaves. After this tree loses its leaves small greenish flowers emerge during the winter and new leaves start over in March. It provides deep shade in the summer but needs space. It can eventually reach 30-to-35 feet high with a 25-to-35 foot canopy. There is a similar hybrid called a Red Push Pistache.
- Arizona or Velvet Mesquite (Prosopis velutina) Give this native tree plenty of room. The mesquite spreads its trunks and main branches in unpredictable and sculptural ways. It needs space to stretch. The tree sprouts white or yellow blooms around May then produces brown pods loved by all types of wildlife. It also offers shade in the summer and sheds most of its leaves for a few months in the winter.
- Desert Willow (Chilopsis linearis) This is a tree that’s only pretty in the summer, but its very pretty. Its showy trumpet flowers bloom from spring through fall in a variety of colors including white, pink and purple. It grows to 25 feet but only about 20 feet wide so it fits nicely into a small yard. This willow also grows pods and loses its leaves in the winter. There are a number of varieties available that produce and drop fewer pods.
- Palo Blanco (Acacia willardiana) The shade this tree provides is filtered through an airy and upright canopy about 10 feet wide, so it’s another option for a small yard. It grows about 20 feet high and has creamy spike-shaped flowers in the spring. The tree is lovely even in the winter when it sheds many – but not all – of its leaves and shows off its creamy white lacey bark.
- Blue Palo Verde (Parkinsonia florida) Arizona’s state tree is a popular and uniquely desert tree with greenish blue bark. It can grow 30 feet high and 30 feet wide. It has multiple trunks and does best in large yards. Foothills Palo Verde (Parkinsonia microphyllum) is another Arizona native. It is smaller, growing to 15 feet high by 15 feet wide. There also are plenty of hybrids that are suitable for smaller yards. Palo Verdes produce a dramatic canopy of yellow flowers in the spring.
Check AMWUA’s plant pages for the trees that are right for your yard. Consider where to plant the tree so it can grow comfortably into its space with minimal trimming. Desert-adapted trees need their foliage to keep them strong and protect them against sun and wind. AMWUA’s plant pages also offer practical information and answer important questions: Is this tree light on litter and pool friendly? Does this tree have thorns, does it attract wildlife, or can it cause allergies? Make sure you understand how to plant, stake and nurture a desert tree. October is the best time to plant a tree but don’t plant before mid September. Trees are valuable to the urban environment and an investment of your time and money. Review your options now before heading to the nursery to reduce impulse buying and a costly mistake.
For 48 years, Arizona Municipal Water Users Association has worked to protect our member cities’ ability to provide assured, safe and sustainable water supplies to their communities. For more water information visit www.amwua.org.