Trees and the California Drought

Submitted by aschellm on
Anne E Schellman

Green tree in the front yard of a house with a dead, brown lawn.
Healthy tree in dead lawn.
If you spend much time outside, chances are you've sought the shade of a nearby tree. Whether walking your dog, visiting a shopping center, or having a picnic, a tree probably made your experience more pleasant. But how much thought have you given to the benefits of trees?

The Benefits of Trees

Trees provide so much more than shade. Here are a few reasons trees are important, courtesy of the International Society of Arboriculture (ISA):

  • Air-conditioning costs are lower in tree-shaded homes & businesses; heating costs are reduced.
  • In workplaces with trees, people report decreased workplace stress and fatigue.
  • Cleaner air: leaves filter the air we breathe by removing dust and other particles.
  • Cooler environment: trees reduce heat in and around parking lots and paved areas.

Trees and the Drought

California residents are being asked to lower their water use by 15%. One easy way to do this is to turn off your sprinklers. But wait! What happens to the trees? Although they may look okay for now, the stress of going without water will take a toll. Lawns can be easily replanted and replaced, but trees take many years to become established.

What do Trees Need?

TRIC Sketch
Although sprinklers provide trees with some water, it's not delivered the best way. Trees need deep, slow, infrequent irrigation to stay healthy. As you can see in this photo, tree roots are just below the surface, in the top three feet. Watering underneath the drip line is best, but not too close to the base of the tree.

How Should I Water My Tree?

There is no “silver bullet” on how often or how much to water. This depends on many factors. Instead, after you water, take a shovel (away from tree roots) and check your soil. How deep did the water penetrate? Make sure water penetrates to a depth of 18” by digging with a shovel. Once that area is dry, water again.

Prioritize Watering Trees with the TRIC

TRIC Set up
One method you can use to ensure your trees receive sufficient water is the TRIC, or “Tree Ring Irrigation Contraption.” The TRIC is designed by researchers at UC Davis using drip irrigation hose placed strategically underneath the dripline of a tree, but not too close to the base. You can visit the California Center for Urban Horticulture for a free supply list and directions on how to create and set up the TRIC. A second method is to purchase a soaker hose and use it in the same way.

For more information about the value of trees, visit the following resources.

Resources

California Center for Urban Horticulture. UC Davis. Tree Ring Irrigation Contraption. https://ccuh.ucdavis.edu/tric

International Society of Arboriculture (ISA). Trees are Good. https://www.treesaregood.org/Portals/0/TreesAreGood_Benefits%20of%20Trees_0321_1.pdf

Water Talk. Janet Hartin. Podcast Episode 21. https://water-talk.squarespace.com/episodes/episode-21

This article was originally published on July 26, 2021.


Source URL: https://ccfruitandnuts.ucanr.edu/blog/stanislaus-sprout/article/trees-and-california-drought