Drought and high temperatures leave Mid-MO trees browning early

Missouri's late-summer heat and dry conditions are stressing trees across the state, but the timing could have been a lot worse.

That's according to Brian Schweiss, a sustainable forestry specialist with MU Extension, who says a late-summer heat wave is better than an early one.

"The good news with the warm temperatures and trees, since it's late summer, is a lot of trees are already starting to kind of shut down for the season," Schweiss said. "If this drought and high temperatures happened early summer, it's much harder on them."

Still, the stress is visible. Schweiss recently traveled through the Lake of the Ozarks area and saw trees browning and shutting down early. He says it's a sign that this year's fall foliage may not be as vibrant as usual.

"What I have seen in some parts of the state... just a lot of trees that are browning and shutting down, and not very much fall color at all," he said. "That's one thing I would anticipate, that we may not have as good a fall color as we would if things would have cooled down and got a little more moisture on the ground here late summer."

Because trees live for decades, Schweiss says a single stressful year isn't necessarily catastrophic, but recovery isn't instant, either.

"Trees are long-lived, so a bad season one year — if it really does cause some root damage or issues with the tree — it can take a few years of good seasons for it to recover," he said.

As tempting as it might be to give struggling trees a nutrient boost, Schweiss says now is the wrong time.

"I would not do any kind of fertilizer applications this late in the season," he said. "Some folks might want to give them a boost of nutrients, but that's not very wise this late in the season, because it could kind of energize them too much, and then if we get some cold weather, they won't be ready to shut down. So it's better just to water, then let the trees shut down for the season."

Schweiss says newly planted trees and those only a few years into the ground are most vulnerable, since they haven't developed the deep root systems that help mature trees weather drought. Watering those younger trees now and into the fall can help support root health even after the leaves have dropped, since roots stay active as long as the soil remains warm.