Lessons learned from the last drought
by Stephanie Robinson
August 3, 2021
California lost hundreds of millions of trees during the last drought, and many more will never recover from a slow decline that started with drought stress. As we enter another drought, we recall a few lessons learned to make sure our trees survive this time around.
Heeding a 2015 call from Governor Brown to conserve water, many Californians turned off their sprinklers and let their lawns turn gold. The grass recovered as soon as rain returned, and other landscaping was easy enough to replace.
But trees took a big hit. Satellite imagery from June 2011 to June 2020 shows canopy loss - the Sacramento region appears much less green.
Many people did not realize that most mature trees need supplemental water in dry months, and some assumed that trees could bounce back even if they struggled a bit.
On top of that, confusion around outdoor watering regulations caused some people to stop watering their trees. In the Sacramento region, trees are exempt from most watering restrictions and schedules when watered with drip irrigation, soaker hoses, hose-end sprinklers, or hoses with a shut-off nozzle.
While healthy trees can recover from short periods of drought stress, prolonged periods without water will eventually kill the tree, and it may take years before the tree finally succumbs. Unfortunately, it will take decades to replace the mature trees we've already lost.
At Urban Wood Rescue, we continue to see casualties from the last drought. Through this program, we divert fallen trees from the landfill so they can continue to provide benefits in the community. If you visit the yard today, you'll find stacks upon stacks of redwood logs waiting for their turn to be milled into lumber.
Once popular when rain was more predictable and our summers were slightly cooler, redwoods are notoriously thirsty trees that are not recommended for our hot and dry inland climate. If you look around any Sacramento neighborhood, it's almost guaranteed that you'll see a few crispy, struggling redwoods rising up above the rest of the tree canopy. But all trees, even drought tolerant species, will need some summer water to survive this drought (except some native oaks).
It can cost thousands to remove a mature tree, and that doesn't account for the loss of health, economic, and environmental benefits that the tree provided. We depend on trees to make our hot summers livable – and unlike other landscaping, trees are irreplaceable.
The good news? Trees don't actually require that much water, and watering trees is affordable. It only costs around $3 per month to water a mature tree. For the price of a coffee, trees clean our air, cool our homes, replenish groundwater, improve our health, and create livable and lovable neighborhoods.
Water is precious, but so are our urban forests – save your landscaping water to keep mature trees healthy and get new trees established.
Here are some tips to save water and save our trees:
- Plant climate-ready tree species that have low water requirements, like our native oaks that are well-adapted to dry summers (SMUD customers - get free trees and a siting consultation to help choose which trees will thrive in your yard)
- Download our printable guide for water wise tree care and share it with neighbors
- Check out our videos to learn how to water both young trees and mature trees
- Thinking about converting your lawn to a water wise landscape? Learn how to protect your mature trees from construction damage and irrigation changes
- Find tips on hiring a certified or consulting arborist to make recommendations for your mature trees
- Water young trees with water collected in a 5 gallon bucket while waiting for your shower to warm up
- If recycling your household water in a gray water system for your landscape, use biodegradable soaps to avoid harming plants with chemicals
- Share this information with friends, neighbors, businesses, neighborhood associations, and schools