Guelph’s city-owned trees getting the EAB treatment

Guelphmercury.com
July 26, 2015
By Joanne Shuttleworth

With the snow gone, winter tree-fall removed and assessments done, the city will now begin treating city-owned ash trees infected with the emerald ash borer beetle.

Timea Filer, a field technologist with the city's urban forestry program, said some trees will be injected with TreeAzin, a pest control product that helps mostly healthy ash trees fight the impact of the disease and retain their health.

If the first round is successful, these trees will likely need another treatment in a couple of years.

Those city-owned trees showing signs and symptoms of emerald ash borer will be removed.

Filer said staff did visual assessments and branch samplings to determine if emerald ash borer was present.

"We went to every ash tree to see if it was a good candidate for treatment," she said.

Trees located in the city's 35 parks will be treated first she said, followed by trees on residential streets.

Holes are drilled at the base of the tree where TreeAzin is injected.

"The chemical is taken up by the tree to the leaves," Filer said. "It leaves the trees in a condition of status quo. So they won't necessarily recover but it will maintain the health of the tree."

Trees that are not treated will eventually die, she said. Those in the most hazardous condition will be removed first. Last week 100 trees were flagged for earliest removal, which will happen in the fall or over the winter.

Trees marked with a blue dot are to receive treatment; those with an orange X are to be removed.

This year the budget for the emerald ash borer program is $528,000. This includes monitoring, assessments, treatment, chemicals, removals, replacement planting and outreach.

Outreach is really important, Filer said, since the city program only covers city trees but the danger is to all ash trees.

So property owners should have their own ash trees assessed by an arborist to see if they should be treated or removed.

"If trees are not treated or removed, there's a risk it can spread," she said. "We really want to push residents to deal with it on the private side."

Signs of an EAB infestation could include: loss of leaves and dead branches in the upper part of the tree; yellowing leaves; adult beetles feeding on leaves; unusually high woodpecker activity; long shoots growing from the tree trunk; vertical cracks in the tree trunk; S-shaped tunnels under the bark, and small D-shaped holes.

Properties with EAB infestation may be exempt from tree removal permits.

Filer said many of the trees lost in the 2013/14 ice storm were ash trees, "and that indicates the level of infestation and the extent of the decline of the tree. It brought the issue to the public as well," she said.

The emerald ash borer was first detected in Canada in 2002. It was confirmed in south-Guelph in 2011 and by 2013 it was detected throughout the city.

Filer said there are about 10,000 city-owned trees at risk, "and that's a big number," she said. "For us, the priority is to maintain the tree canopy as much as we can."

Filer said they will replace the ash trees with native, non-invasive varieties of maple, oak, common hackberry, serviceberry and Kentucky coffee tree. She said ginkos, cherry trees, and lindens are non-native trees that might also be good candidates as they are urban tolerant.

"That's our next challenge," Filer said. "Salt, heat, drought, construction - there are all kinds of stresses on urban trees."

This is Year 2 of a 10-year program to deal with the infestation.

Anyone with questions can check the city's website guelph.ca/trees or guelph.ca/eab. You can also reach Filer at 519-824-1260 ext. 3352 or at timea.filer@guelph.ca.