Summer is a great time to see how your tree is really doing, says Jacob Rogers, a certified arborist.

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Seattle summers are brief, but increasingly, hot and getting hotter. Your trees and other greenery aren’t any more used to these temperatures than you are. But there are several ways to keep your trees healthy and happy, as well as methods to make sure they aren’t dying from the heat.

Take stock of the tree’s overall health

Summer is a great time to see how your tree is really doing, says Jacob Rogers, a certified arborist who works at Eastside Tree Works.

First, clear the deadwood. It helps keep your yard safe and your tree healthy.

“The winter’s good to prune the trees because that’s when the trees are dormant,” Rogers says. “In summertime, it’s good to take the deadwood out, because it’s easy to tell what’s dead or what isn’t.” Conifers with no leaves or needles are dying or dead, especially if those branches on the end of the canopy are dry, are an indication of a dead or dying tree.

This clearing of deadwood also helps keep your house safe. “It’s a really good way to help fireproof your tree,” Rogers says. “If you collect a bunch of deadwood, especially like in a conifer, like a spruce next to your house, that’s all kindling that can go up really easily.”

Look for signs of distress


If you start seeing mushrooms and conks on a tree, that’s an indication that there’s some decay on the inside, especially if you start seeing mushrooms growing around the base of a tree around the roots,” Rogers says.  “And at that point, it’s almost impossible to preserve a tree.”

Another sign of distress, says Rogers, is a crack in the trunk or the wood splitting.

Dead branches without foliage indicate that a tree may be dying, says Chris Selle a TRAQ-certified arborist, with Eastside Tree Works. If a tree is 40% dead, then it might not be recoverable. “Then it’s typically not going to come back with some simple watering or chemical intervention.”

Pest infestations

The Pacific Northwest doesn’t have a huge problem with pests in trees but there are two to keep an eye out for: termites and the bronze birch borer.

“Summertime is a definitely a good time to examine your trees, especially if you have birch trees, which are really subset susceptible to the bronze birch borer,” Rogers says. These pests build little tunnels inside the tree.

“If you have a birch tree and if and the top dies, and the lower portion is still alive, there’s a good possibility that you have the bronze birch borer,” he says. They are so contagious that many nurseries have stopped selling birch trees.

Ornamental trees sometimes attract aphids, says Selle, but he adds that aphids are “more of a nuisance than detrimental to the tree most of the time, but people typically don’t like them because there can be hundreds and hundreds of them. And if you get enough of them, they can kill the tree eventually.”

He recommends getting diatomaceous earth, a natural substance that helps a lot with aphids.

For termites, look for signs of sawdust. If it’s still early, Rogers says calling pest control may help, but if they’ve eaten though the core, the tree may need to be removed.

Drought-proof your tree

We are pretty lucky up here in the Pacific Northwest because we get so much rain, but the heat of summer means that our trees get a little thirsty. Birches and hemlocks have a harder time than the firs and evergreens.

“If it’s thirsty or needs water, it’ll start to wilt,” Selle says. “The leaves and the foliage will feel dry and crispy.”

If you suspect your tree is thirsty you can add another drip line or watering cycle to the tree.

Selle says to water during the coolest part of the day. “Water in the evenings, typically, or early in the morning. Just don’t do it right in the heat of the day.” Add an extra 15 to 25 minutes to the watering cycle if the tree isn’t getting enough water. In summer, he recommends four or five days a week of watering.

Other tips for tree care

Selle recommends adding good fertilizer to the soil. “It’s never a bad idea to just put a balanced, slow-release fertilizer down around your smaller to medium ornamental trees with the watering if they’re exhibiting signs of stress.”

Grass is even thirstier than trees so remember when watering. “You want to have dirt or beauty bark, something less competitive than grass right around the tree,” Rogers says.

And you’ll want to avoid leaving stagnant or large amounts of water around the base of a tree. Rogers says to make sure not to overwater or water directly on the trunk. “That’s why trees drown.”

A little hot-weather TLC will help trees survive the summer and flourish for the fall.

Eastside Tree Works has been providing commercial and residential tree services to Seattle and the Eastside area since 2005. From 24-hour emergency service to tree pruning or removal and stump grinding, Eastside Tree Works delivers professional workmanship at competitive rates.