SAN JOSE (KPIX 5) — It’s easy to see the beauty and benefits of large, mature trees. What’s harder to see is that the drought is already putting many of them under stress.

“If you notice things that for this time of year look a little different,” said John Chapman, an arborist for the Santa Clara Valley Water District. “Like, a lot of our trees will start to turn color in the fall as just part of their natural progression. We’re seeing plants starting to do that already.”

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Chapman says other trees, which were probably stressed in the last drought, have now died. And more could follow in the yards of homeowners when people turn off their lawn sprinklers to save water.

That’s why the Valley Water District is modifying its message when it comes to watering during the drought.

“The messaging is to cut back on general use of water in your landscape, convert over to drought-tolerant landscaping, but if you have established trees, give them water.”

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Mature trees provide shade and natural cooling, which can cut down on home energy use. They also provide habitat for birds and wildlife, cut down on erosion and provide oxygen for us to breathe.

“You can’t just replace a large mature tree like that. You need to plant the tree and wait and wait, 30 to even, like, hundreds of years,” said Sophia Saavedra with Our City Forest, which helps replenish San Jose’s tree population.

Saavedra says mature trees should get a deep watering twice a month during the summer season and newly planted trees should get a soaking twice a week.

The water district recommends using a soaker hose to wet the roots as far out as the tree’s drip line, to water only in the morning or evenings, and to use a thick natural mulch around the base of the tree, to hold the moisture in.

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“We really advocate for deep, infrequent watering,” Chapman said.