Save Our Water and Our Trees
Preserving California’s Urban Trees During Drought
Trees cool our streets and our homes, reducing energy costs and saving lives during heat waves.
- Trees help make our communities more climate resilient.
- Trees improve air and water quality.
- Trees provide shade to the landscape and reduce water needs.
- Trees slow stormwater runoff and help recharge groundwater.
- Trees add value to our homes & neighborhoods.
- Trees make our streets more inviting for walking and biking.
Trees and water are both precious resources. Without watering through dry seasons, we risk losing these benefits from our urban trees. It will take 10, 20 or even 50+ years to grow back mature trees.
Tips for Tree Care During Drought
- For established trees (3+ years old), slowly soak the root zone out toward the drip line –the area under the farthest reaches of the branches– until water soaks 12-18 inches below the surface. Do not water close to the trunk.
- You can use a soaker hose, a sprinkler hose attachment on a low setting, or other systems. If you choose to use a drip system, monitor it to make sure it’s functioning, add emitters in the tree’s root zone, and increase the water.
- The roots of a young tree are located mostly near the trunk. Young trees need 5 gallons of water 2 – 4 times per week. Create a small watering basin with a berm of dirt. One method is to drill a small hole near the bottom of a 5-gallon bucket, place it near the tree, fill it with water, and allow it to slowly drain into the soil.
- Mulch, Mulch, MULCH! 4 – 6 inches of mulch or leaf litter improves vigor and helps retain moisture, reducing water needs and protecting your trees.
- Let the soil dry between waterings – trees need oxygen too!
- Avoid pruning or fertilizing trees during dry seasons. Lack of water and too much pruning both stress your trees. Fertilizer encourages leafy growth, which requires more water.
- Conserve water all the time: Shower with a bucket and use that water for your trees as long as it is free of non-biodegradable soaps
Resources

Save our Trees
California ReLeaf partnered with the Department of Water Resources to share information to the public about prioritizing tree care as part of water conservation. Take a look and share the info!

Partner Sites
Our Network members and partners have more great information available about drought and tree care:

Spread the Word
Together we can get the word out and save millions of trees! Here are flyers and marketing materials your organization can use for your drought messaging.
- Trees and Drought Flyer English / Spanish
- We Need Trees, and Trees Need Water Flyer by Sacramento Tree Foundation
- SOWAOT Logos
- Social Media Tool Kit (Coming Soon)
- Save Our Water Webinar (Includes a discussion about messaging)
Tree Care Guidance
These simple, informative tree-watering videos teach you how to care for your tree during drought:
FAQ: Trees & Dry Season in California
Why do I need to take care of my tree during the drought?
- Trees improve air and water quality
- Trees provide shade to the landscape and reduce water needs
- Trees help keep your home cooler
- Trees slow stormwater runoff and help recharge groundwater
- Trees reduce soil erosion
- Trees add value – sometimes thousands of dollars’ worth – to your home & neighborhood
Trees take a long time to grow. Without helping our trees through the drought, we risk losing their benefits. While the drought may not last long, it can seriously damage or kill trees, and these benefits will take 10, 20, or even 50+ years to get back. Taking care of your trees during the drought ensures that we preserve and protect these life-giving benefits for ourselves, our families, our homes, and our communities.
Click on the videos below to learn how to care for your mature and young trees.
These videos are available in English and Spanish.
How can I tell if my tree needs water?
The amount of water your tree needs depends on your soil and tree type. You can check the soil moisture to see if it’s time to water. The easiest way to check soil moisture is to take a long (8”+) screwdriver and poke it into the soil. It will pass easily into moist soil, but be difficult to push into dry soil. If you can’t poke it in at least 6”, it’s time to water. This technique works best in clay and loam soils
Why not just let my trees die?
Some drought-stressed trees, once too dried out, are unable to absorb water once the rains return or you finally begin watering them. Drought stress affects the long-term health and vigor of trees. Your tree may look fine this summer, but die next summer if not watered now. Grass can grow back in just a few weeks, but it can take decades for a tree to grow to full size.
How does supplemental watering help in summer and dry seasons?
How often should I water my mature drought-tolerant trees?
Don't my trees get water when I water my lawn?
Where can I get more info on how to care for my trees?
- Check back often at http://SaveOurWater.com/save-our-water-and-our-trees/ for new information on how to care for trees.
- To learn about programs in your neighborhood, you can check with:
- Your local urban forest nonprofit. To locate an urban forest group near you, visit https://californiareleaf.org/network/map/
- Your local UC Cooperative Extension. Visit http://ucanr.edu/County_Offices
Tell me more about mulching.
- Reduces the amount of water needed in your yard by 10 – 25%
- Decomposes and releases nutrients into the soil
- Reduces soil compaction so roots can breathe
- Maintains soil temperature and protects roots from cold and heat
- Discourages grass & weeds – which compete for nutrients – from growing near the tree trunk
Spread mulch in a 4- 6 inch layer around your tree – your tree would love the mulch to be as wide as the canopy of the tree. You will need to either remove the lawn underneath the mulch or “sheet mulch” with cardboard or newspaper to prevent the grass from growing up through the mulch. Keep mulch 2 – 3 inches away from the tree trunk to prevent rot around the base of the tree.