Caring for Trees in a Low Water Landscape
As the lack of water continues to be of great concern, our urban forest is in need of extra care. Read these simple ways to care for your trees while saving water and download our Tips for Tree Care During Drought handout (en Español).
Know Your Watering Rules
Each city and county has different rules for outdoor watering. Be sure you know which days of the week you can water your trees. Check out this map from BeWaterSmart to look up watering guidelines for your address.
Add Mulch Around Your Trees
Natural, wood chip mulch is one of the best ways to save water and can keep your trees healthy. A thick layer of mulch on top of the soil around your tree will keep moisture in the soil and protect the roots from extreme temperatures, so you use less water and your trees stay happy!
Keep mulch 4 inches away from the trunk, spread it 4 feet in diameter (or out to the drip line if possible), and pile it 6 inches deep.
Check the Soil
How do you know if it's time to water your tree? Check the soil!
Use a small shovel or screw driver to check the soil 6-8 inches below the surface near the drip line.
If the soil feels dry and crumbly, it's time to water your tree with a slow soak. If the soil feels sticky or wet, let it dry for a couple days before checking it again.
Water Responsibly With a Slow Soak
Water needs to reach the roots of your tree, which are located 12-28 inches below the surface. Because the root zone extends as a tree grows, young trees and mature trees need different watering techniques.
Watering Young Trees (1-5 years after planting)
The roots of a young tree are mostly located near the trunk and grow 12-18 inches below the surface.
A young tree needs 10-15 gallons of water per week. Slowly soak the area near the base of the tree 2-3 times per week with 5 gallons each time.
You can use:
- Drip irrigation
- A soaker hose
- The bucket method below
The Bucket Method:
1. Collect water in a bucket while your shower warms up.
2. Drill a small hole (1/8") near the bottom of a second bucket and place it near the trunk of your young tree.
3. Fill second bucket with the shower water you saved. The water will slowly drip into the soil and keep your tree healthy.
Your young tree only needs 10-15 gallons of water per week. That's the same amount of water used in a 6 minute shower!
Learn more about caring for your young trees.
Watering Mature Trees (5+ years after planting)
The roots of a mature tree extend underground even wider than the branches extend above ground. Adding water near the trunk of a mature tree will not reach the roots.
Slowly soak the area throughout the root zone for several hours to reach the roots 12-18 inches below the surface.
You can use:
- A soaker hose beginning a few feet from the trunk and spiraled outward toward the drip line
- An oscillating sprinkler on a low setting moved to various locations through the root zone
- Drip emitters
Allow water to slowly drip into your soil for several hours.
If your root zone extends under hardscape or beyond your property, slowly soak as much of the root zone as possible.
Learn more about caring for your mature trees.
**Native trees like, valley oaks, which have never received regular irrigation may be harmed by adding extra water. Contact a Certified Arborist if you have questions about the health of your native or mature trees.