This year’s weather has had some unusual turns, with a long, cold spring that felt more like winter and then periods of high heat and dry conditions in the summer. And while the weather throughout the year affects the color of the leaves in the fall, weather conditions in the months leading up to fall have the biggest impact, said Sharon Yiesla, plant knowledge specialist at The Morton Arboretum’s Plant Clinic.
“Adequate rainfall would be helpful, as well as sunny days followed by cool nights,” Yiesla explained.
Luckily our summer dry spell didn’t last too long, because heat and drought can be a showstopper for the fall color.
“If heat and drought cause leaves to be scorched, no amount of good fall weather will make up for that,” Yiesla said.
In fact, the trees we are seeing now that already have leaves starting to change color or drop are likely stressed, possibly by high temperatures and drought-like conditions, she said.
One thing that can help extend the fall color season is a nice frost in early October, Bryerton said. This is especially true if the weather then warms up again. The frost triggers the tree to prepare for winter, which will cause the leaves to change color. If it’s followed by a mild stretch, the brightly colored leaves will stay on the tree longer before dropping.
On the other hand, windy, rainy and stormy conditions can shorten the period of time when we can enjoy the color because the leaves will be knocked to the ground sooner, he said.
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