Experts school Sarnia-Lambton on looming oak killer

TheObserver.ca
March 28, 2018
Tyler Kula

At least one Sarnia-Lambton tree company is changing how it prunes to help prevent the spread of tree-killing oak wilt.

“You really only want to prune an oak tree in the wintertime and we’ve prepared to take that financial crunch,” said Tim Wilkins, owner of Wyoming Tree Service.

He, other tree company officials, forestry department workers and various other community members packed council chambers Wednesday at city hall to hear experts from Ontario’s Ministry of Natural Resources and Michigan – where more than 500,000 state-park oak trees have been lost to the fungal disease since 2009 – speak about the looming invasion.

“The importance of this is to get it in the beginning, to find it when it’s just a small stand,” said Phillip Kurzeja, a Comber, Ontario native working in Michigan, and who Sarnia Forestry Manager Patti Ross called the best oak wilt field technician in the state.

“Because this can very easily get out of control,” he said.

The vascular disease that can kill certain oak species in as quick as 30 days was first identified in the 1940s and has spread across much of the United States.

It’s hasn’t been found in Canada, but has been confirmed half a kilometer from Windsor, on Belle Isle.

“Which is scary,” said Kurzeja, who’s travelled around Michigan identifying oak wilt as the state fights to stop its spread.

It’s hard to believe it’s not already here, said Wilkins, noting he plans to investigate some local sites for signs of oak wilt.

“I think it’s awesome the City of Sarnia is trying to be involved the way they are in educating the public,” he said. “It’s the only way you are going to stop it is by doing that.”

The disease is spread by picnic bugs drawn to sap, when it’s exposed by cuts in the bark, including via pruning.

The main messaging to keep oak wilt in check is don’t prune when the sap could potentially attract beetles between April and July, and don’t transport firewood because it could be infected.

Roots grafting between oaks can also spread the disease that manifests with leaves bronzing and falling to the ground.

Vertical bark cracks can indicate fungal spore mats growing underneath.

“Become educated, learn about the disease, learn what it looks like, and if you see something make a phone call,” said Kurzeja. “That’s the best thing to do.”

The Canadian Food Inspection Agency is the contact.

“Public participation is going to be really crucial to moving this forward,” said Richard Wilson, forest program pathologist with the Ministry of Natural Resources.

“Emerald ash borer, it’s gotten away from us,” he said, referring to the invasive beetle that devastated ash populations starting in the mid-2000s.

“But oak wilt, it doesn’t have to get away from us.”

Wilkins is skeptical and said having some sort of bylaw that prevents people from pruning without a permit would be useful.

City council rejected a proposed tree bylaw last year amid public protests it was too onerous.

“It would have been nice if they could have diluted it down a little bit,” Wilkins said.

“There are too many people who are looking for the right price and they’re not looking for the education,” he said.