Time to take care of your (valuable) shade trees

In summer, shade trees can be your best friend. It’s also the season when those trees need some extra TLC.

Why value shade? Mature trees lower the temperature in your landscape – and your home, too.

“Trees literally save lives,” says Kayden Rosenbauer, community arborist with the Sacramento Tree Foundation. “Heat-related deaths are among the top reasons for all fatalities. A neighborhood with proper shade trees can be up to 20 degrees cooler than a place with no trees. When it’s 100 degrees or hotter, that 20 degrees makes a huge difference and saves people’s lives, too.”

Shade has many other neighborhood benefits, too, such as better air quality and more walk-able streets.

“Trees help clean the air of pollutants,” says Rosenbauer, noting the vital difference trees make after wildfires to clear smoke. “Their leaves act like filters while putting more oxygen into the atmosphere.”

Besides lowering temperatures and cleaning the air, shade trees also beautify streets and make neighborhoods automatically more inviting for outdoor activities; that’s good for everyone.

At SacTree, Rosenbauer helps local residents embrace their shade – and plant more. In 2024, he personally gave volunteers a hand in planting more than 1,500 trees. In addition, SacTree’s Shade Tree Program – in partnership with SMUD – gave away 13,000 free shade trees last year. Many of those trees replaced ones that had fallen during winter storms or were weakened by disease or age.

Summer heat stresses trees of all sizes and ages, Rosenbauer notes. That’s when they need added care.

“Trees can be incredibly resilient,” he says. “If not cared for properly, trees can still hang on somehow, but they don’t really grow or develop as they should.”

Young trees need different care – and watering schedules – than mature trees that have reached their full height.

“When young, trees need more consistent watering – three times a week during summer,” Rosenbauer says. “You also want to encourage them to grow deep roots; that helps them through the stress of summer.”

Slow, deep irrigation can prompt that important root growth. For young trees, Rosenbauer recommends the “bucket method.”

“Take a 5-gallon bucket and drill a small 1/8-inch hole in the bottom,” he explains. “Place the bucket near the tree and fill it with water. Do this a few times, rotating the bucket around the tree.”

For older trees, get a soaker hose.

“Mature trees need a different watering method,” Rosenbauer continues. “Don’t water near the trunk; water at the dripline, the outside edge of the tree’s canopy.”

Big trees have their most active surface roots along their driplines – where rainwater would normally drip off the tree’s foliage. Encircle the tree with a soaker hose, lined up just inside that dripline, and give the tree a deep soaking once a week during summer heat or as needed.

“Every tree is different – different soil, different species, etc. – so frequency will be different, too,” he adds. “Before you turn on the hose, check the soil moisture. Take a long screwdriver. If you can’t push it 6 inches deep, it’s time to water.”

To preserve that moisture, make sure to mulch around trees. Use wood chips, shredded bark or other organic material; it adds nutrients to the soil as well as maintains moisture and cooler soil temperatures.

“For mulch, remember the ‘4-4-4’ rule – 4 feet wide, 4 inches deep and 4 inches away from the trunk,” Rosenbauer says. “Mulch makes a huge difference for trees of all ages.”

For shady summers for years to come, take time now to care for those leafy assets.

“Pay attention to your trees,” Rosenbauer says. “They need love, too.”

For more on watering trees, see https://sactree.org/tree-care-tips/how-to-water-trees/

For more on mulch, see https://sactree.org/tree-care-tips/how-to-mulch-trees/