Choosing the Right Tree

There is ongoing discussion about the benefits of some trees over others.  Trees for Tucson encourages planting primarily native trees (those that grow naturally in the Sonoran Desert) versus non-native trees (exotic species from elsewhere). The criteria for choosing trees are:

- Shading buildings: The primary objective of the Trees for Tucson program is to reduce energy use by shading residences. The most effective way to accomplish that objective is to provide desert shade trees for energy conservation.

- Maintenance: For many years the most popular shade tree was the Chilean Mesquite. However Chilean mesquites require more maintenance than native velvet mesquite and are more vulnerable to wind damage as they grow larger. Be aware that planting any tree will require some level of maintenance over time, and that periodic, planned maintenance is much better than infrequent, heavy pruning or emergency maintenance.

- Water Use: To reduce water use there are both low water use native trees (velvet mesquite, blue palo verde) and non-native trees (Texas Ebony) that do well in Tucson. Planning water harvesting to your tree planting location will increase shade, reducing energy use and improving aesthetics!

- Thorns: Many residents prefer to avoid thorny trees. This is the main reasons native trees such as Velvet Mesquite or Blue Palo Verde aren't always appropriate from a homeowner’s perspective. Desert Willow and Red Push Pistache are popular for this reason.

- Narrow Planting Spaces: Many new home developments have narrow yards between homes, but are often where shade is most needed.  Work to plant trees in places at least 10-15 feet from homes. 

- Pollen and Allergies:the Desert Willow  is a great choice for those who want a beautiful tree with lovely Spring/Summer flowers and is also low pollen. Some desert trees are also very high-pollen for brief periods of the year.

- Late Fall/early winter color: The Red Push Pistache is a heat and frost-tolerant non-native tree, providing excellent shade as it grows, and requiring only slightly more water, while exhibiting a brief show of color before dropping its leaves in a short time during the cold time of year.

- Frost tolerance: native trees are the best adapted to our local temperature extremes. Some non-native trees are heat and frost-tolerant and do well here without displaying invasive (rapid spread) characteristics. 

- Invasiveness: Avoid non-native plants that are categorized as highly invasive or noxious, exhibiting a more rapid spread throughout the community and can become invasive. Bufel Grass and African Sumac (rhus lancea) is now avoided due to its known invasiveness (spreading by suckers as well as seed).

- Wildlife Use:  If you want to attract wildlife, your best bet is to plant a diversity of trees, shrubs and groundcover that provide two necessary components for animals: food (including insects) and cover. Birds, lizards and small mammals feed on the insects and seeds found in the living and dead plant material. Keeping your yard free of this material reduces wildlife habitat value.

- Palm trees: avoid 

- Taller introduced trees such as eucalyptus and pine attract owls and raptors such as red-tailed hawks, Harris’ hawks and Cooper’s hawks that  wouldn’t be as common in the Tucson area. These taller trees can offer great shade but will also require substantial long-term, professional maintenance. Tall trees that are native (i.e. cottonwood) require huge amounts of water, so are found long major watercourses. 

 

For more information call (520) 791-3109 or email tft@treesfortucson.org.