Why Some Leaves Are Already Changing Color In Wisconsin

Some trees in the state are already changing color and dropping leaves due to a recent dry spell and wildly variable weather patterns since last year.

Even though the temperatures across the state are pushing the 90-degree mark this week, some trees in the Chippewa Valley are already going dormant – changing their colors and shedding their leaves. It seems like a paradox, but according to forestry officials this is a normal reaction to stress.

Todd Lanigan is a forestry health specialist for the Department of Natural Resources based in Eau Claire. He says trees are still stressed out from last year’s hot and dry summer.

“Trees aren’t like houseplants, where if they start getting wilted and dry you give them a shot of water and they spring back,” says Lanigan. “Trees are going to take a couple years to recover from a drought like last year.”

Lanigan says the drought lowered resistance to disease and bugs. He also says some trees are impacted more than others and there have been significant die-offs of pines, spruce and tamarack.

Bill McNee, the DNR’s forest health specialist based in Plymouth, has also noticed some trees and shrubs changing color early. McNee says the last couple of years have been rough on Wisconsin’s forests.

“It’s been a very variable the last couple of years for the trees because it was very wet, then it was very warm and dry last summer, then it was very wet this spring, and now it’s dry again,” says McNee. “So the trees are being exposed to very variable fluctuating conditions, which is stressful for them.”

McNee says some good soaking rains would go a long way to help keep leaves from changing too soon but the lingering effects of these stressful summers will last a couple more years.