New Brunswick

Fredericton plans to increase efforts to combat Dutch elm disease

Fredericton is doubling its efforts to protect its trees against Dutch elm disease, a tree-killing fungus.

'We're down to about 1,000. Our hope is to save the elms," city arborist says

Keanen Jewett stands in front of an elm tree in downtown Fredericton. (Gary Moore/CBC)

Fredericton is doubling its efforts to protect its trees against Dutch elm disease, a tree-killing fungus.

The disease spreads from elm bark beetles feeding under the bark of the tree during winter.

Last year, the city inoculated 124 trees with a vaccine called DutchTrig, a biological and organic control agent.

It plans to double that number this year, said city arborist Keanen Jewett. The city plans a "proactive" treatment-based approach rather than removing infected trees.

"It's what we feel is probably the best and only control we have other than [removing trees]," Jewett said.

Dutch elm disease can cause a tree's branches to wilt and its leaves to turn yellow in the middle of the summer. 

The city cut down several elm trees last year to prevent the disease from spreading. Jewett said more could be cut this year, if necessary, but inoculating trees is cheaper than removing them, according to a news release from the city.

The DutchTrig vaccination is designed to protect trees from becoming infected with the disease. It isn't able to cure infected trees.

"At one time, we had a huge population of elm trees, well over 7,000 estimated in the city," Jewett said. "We're down to about 1,000. Our hope is to save the elms."

Fredericton inoculated 124 elm trees last year with a vaccine called DutchTrig, a biological and organic control agent. (CBC)

The city doesn't survey trees for Dutch elm disease until around mid-July, Jewett said, so it won't know how many are infected until then.

Trees inoculated last year will have to be treated again because trees grow an outer layer each year that's subject to infection, Jewett said. 

The DutchTrig vaccine is only being used on trees that grow on city property. For trees on private property, Jewett said the city plans to advise residents to use DutchTrig on their trees as well.

But the cost isn't covered by the city, which means homeowners will have to pay for the vaccine. Jewett estimates the cost of inoculating one tree is up to $150. 

"If we did come up with a program that maybe we could encourage people to piggyback on, then we'd maybe have the hopes of reducing the costs a little bit to make it more feasible for people."

With files from Gary Moore

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