QCA oak trees suffering in drought conditions, susceptible to pests

Fall is usually when people pay attention to trees to see the changing leaf colors. But homeowners should be paying closer attention to their oak trees. Robert Spartz, district manager for the Davey Tree Expert Company in Eldridge, spoke with Our Quad Cities News via Zoom to discuss how people can protect the trees in their yards from damage.

“The last couple years have been really rough for our oak trees in general, seeing a lot of general decline of the oak trees,” he said. “Over the last two months, we’ve received about three quarters of an inch of rain. That’s including the month of September, which we got .6 inches of rain, and this month we’ve gotten roughly about a quarter inch of rain. The drought factor is real. We’re in an extreme drought right now. Everything is very dry. If you’re not watering your trees, you’re not helping them out, to help them survive and persevere and keep the vigor up.”

When drought conditions put stress on trees, they’re more vulnerable to viruses and pests. “So one of those would be two lined chestnut borer,” said Spartz. “It’s an insect. It looks exactly like an emerald ash borer, except it’s a different color. A lot of people can be confused because it’s called chestnut borer and the only reason it’s called chestnut is because of the color of the insect itself. The chestnut is a brownish color. The insect is like a shiny brown, metallic color, and it looks exactly like emerald ash borer, except it’s brown versus green.”

Spartz says homeowners with trees need to be aware that they should water trees at least as often as they water outdoor plants or the yard. “It is getting warmer here on a consistent basis. We’re in the first full week of October, and temperatures are hitting the low to mid 80s. As our as our climate is changing a little bit over time, we’re starting to see drastic impact on the oak trees themselves. And when the oak trees are stressed, they’re more susceptible to viruses and things like that.”

“In the Quad Cities, we have oak wilt, which is our number one outright tree killer,” he said. “Watering your tree properly, mulching your tree, fertilizing your tree, potentially applying preventative insecticides to combat insect problems, doing fungicide applications – that can help minimize the impact of oak wilt. Oak wilt is a fungus that will get into the tree. It blocks the flow of water and nutrients to the upper canopy, and the tree can sometimes die quickly and sometimes die very slowly. A lot of it depends on how much water we have in the ground. Right now, if a tree was to contract oak wilt, we’d probably see a pretty quick death on that tree.”

Spartz says it’s always a good idea to call a professional with questions. “The best thing to do if you have any questions would be to call a certified arborist, talk to them and get some general recommendations and guidelines. An ounce of preventative is worth a pound of cure. These are the times where upfront, spending the time and potentially the money to do what’s needed for the tree in a preventative state is going to be worth it. Our oaks are consistently struggling. I’m seeing more and more die every year. It’s become a very sad state as far as the oak tree community goes here. We definitely don’t want to lose all our oak trees. The more vigor that we can pump into these trees, and the happier we can keep them, the better off we are.”

“Watering is the number one thing, especially during a time like right now. We need to focus on the tree being able to supply the water and nutrients and not lose foliage early in the season, which can happen when we run into a drought. We’re seeing a lot of different other trees change as well, too. Right now, I still think we’re running about two weeks early than where we should be. For instance, the maple trees, a lot of them are turning red at the tips or maybe halfway through the canopy at this point.” He says an initial watering period of several times over two weeks, followed by about an inch of water a week will protect oak trees.

“Oak trees, younger trees, a lot of different trees out there right now are in a stress state. We don’t need to talk just about oak trees, just trees in general. They’re very important to the community. They’re very important to the world. Taking a little bit extra time and effort to fertilize, water, mulch help keep these trees as healthy as we can for as long as we can.”

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