Jeff Iles, a horticulture professor at Iowa State University, says the wide weather swings we’ve seen in the past year have had a significant impact on many trees across the state.
“All of these environmental stresses build on one another,” Iles says. “You have cold, then you have wet springs, and then it was hot and dry this summer. In fact, it seemed like there were two months where it didn’t rain and it was dry. That put a lot of trees and shrubs into a stress mode.”
Some trees were blooming in mid-fall instead of during the spring — completely backwards from the norm. Other trees lost their leaves early or are showing other signs of stress. Iles says there’s no easy fix.
“We go back to right plant, right place,” he says. “If we’ve chosen appropriate plants for the landscape, then they’ll be able to weather these extremes. Really, all we can do is wait and pick up the pieces at the other end. It’s always dicey. We always want to know how the plants are going to respond and what they’ll look like come spring.”
Since wet conditions promote a variety of tree diseases, Iles recommends planting trees that are known to withstand adverse conditions, such as choosing a bald cyprus tree for a flood plain. Just like Iowans wouldn’t likely try to plant palm trees or orange trees, which only thrive in tropical environments, Iowans -should- plant native trees, like boxelder, silver maple, red oak, prairie crabapple and the eastern cottonwood.
“We can prune, we can fertilize, we can water when necessary, but if we’ve made the right choices in the landscape, chosen the right plants, than a lot of these problems are not as dire as they might seem.”
Plants that flowered this fall aren’t necessarily going to die, he says, but they likely won’t have a typical full bloom in the spring. Still, they’ll probably make it through the winter ahead just fine.
Iles made his comments on the Iowa Public Radio program, “Talk of Iowa.”
Thanks to Charity Nebbe, Iowa Public Radio