© 2024 WXPR
Play Live Radio
Next Up:
0:00 0:00
Available On Air Stations

Help prevent the spread of oak wilt by putting off pruning and cutting until after July

Oak Wilt
Wisconsin DNR
This is what oak wilt infected trees look like by summer; dying leaves stand out against other green trees.

It looks like spring might actually be coming to the Northwoods this week.

As the temperatures start to warm up and the snow melts many people will begin some outdoor clean-up.

The Wisconsin DNR is urging people to do their part to prevent the spread of oak wilt.

Oak wilthas slowly been making its way into Wisconsin’s northern counties over the last five or so years.

There are only seven counties in the state without any confirmed cases.

“Over the last probably five years we’re seeing more oak wilt infections in Northern Wisconsin for a variety of reasons. The disease has taken some time to get up here. People moving firewood around, firewood logs. And then also, construction in new areas is causing trees to get injured during the risky period which is April through the July and then end up getting infected with the disease,” said Paul Cigan, plant, pests, and disease specialist with the Wisconsin DNR.

Oak Wilt is a disease that kills oak trees, especially the red oak group.

“What it ends up doing is wilt out and lose their leaves very quickly after infection and the infection typically occurs in the early months of spring and summer, but then the symptoms start to appear about mid-July through the end of September. Trees, once infected, die very abruptly, within a matter of weeks,” he said.

The disease is most often spread by beetles carrying the oak wilt spores from infected trees to healthy ones that have an exposed wound.

“The next problem is that once that tree is infected, the disease can then move into the stem down into the root system and connect to oaks that may be growing adjacent within 20 up to even 100 feet of another oak. Those are then subject to potential infection through the root graft,” said Cigan.

Because of this, the Wisconsin DNR asks people to hold off pruning or cutting oak trees until after July.

If you have to take down a branch or limb for safety reasons, Cigan recommends applying a pruning sealant or latex-based paint onto the fresh cut surface within 15 minutes of the cut.

Cigan says if a tree on your property dies of oak wilt you should contact the DNR or an arborist.

“There’s a lot that can be done to slow or stop the spread of oak wilt, especially on the below ground side where it can spread through the root grafts, however that requires generally much more involved assessment. It’s great to get a hold of a certified arborist for that type of assessment or if it’s more of a wood lot and a forest level situation to contact the local DNR Forest Health Specialist,” said Cigan.

You want to look for leaves falling quickly off an oak tree between July and September. Cigan says if the edges have a brown or bronze coloration that’s usually a sign of oak wilt.

Because of the heavy snow still on the ground in Northern Wisconsin, Cigan says people have a little extra time this year to cut and clean up before the beetles that spread the disease emerge.

You can use this tool to determine the risk of oak wilt at any given time.

Katie Thoresen is WXPR's News Director/Vice President.
Up North Updates
* indicates required
Related Content