I’m not usually prone to such behaviour, but a tree at the front of our home deserves a hug. It’s a lovely, big shade tree, at least 50 feet tall. Planted on the city boulevard adjacent to our property, it keeps the front of our home cool in the summer. Our yard is otherwise bare of trees, and without this beautiful one our front lawn would surely bake, and the temperature inside our home would rise by several degrees on a hot day.
Likely planted when our home was built, some 64 years ago, it’s just one of hundreds, if not thousands, of similar trees in our neighbourhood. At least it was until recently. Many of its companions have been chopped down this year, due to damage by the voracious Emerald Ash Borer.
Our ash tree is not yet one to be marked by city crews with a big red “X”, but it may well be living on borrowed time. The Emerald Ash Borer, a wood-boring beetle native to Asia, has infected thousands of trees in Ottawa and the destruction is heartbreaking. Our neighbourhood has seen dozens of trees felled, leaving a giant gash in what was once a beautiful canopy.
Ash tree showing signs of borer damage
In one park in Ottawa alone this spring, up to 1,000 trees were cut down.
The beetle is not very adept at flying, so much of the problem has to do with wood being moved from one spot to another. Even when a tree is cut down, the Ash Borer remains beneath the bark of the wood. Firewood is a huge problem and a big reason the beetle has spread from Michigan, through Ontario and now into Quebec.
One-quarter of Ottawa’s trees are ash. Ironically, many were planted to replace elms killed by Dutch Elm Disease.
According to Natural Resources Canada, Emerald Ash Borer was first detected in Canada in Windsor, in 2002. By 2005, it had spread into the counties of Essex and Lambton and the municipalities of Chatham-Kent and Dutton/Dunwich. In 2006, it was detected in London, Ontario, and in 2007, new locations were detected as far east as Toronto. The insect has continued to spread in Ontario, with infestations found as far north as Sault Ste. Marie and, by 2011, as far east as Ottawa, Prescott-Russell and Leeds-Grenville counties in eastern Ontario.
One of thousands of ash trees in Ottawa cut down after being weakened by the Emerald Ash Borer
Many of the trees are too far gone, but some can be saved. One solution that avoids cutting down trees is the use of TreeAzin, an insecticide derived from seeds of the Neem tree. It was granted emergency registration in 2008 for use as a systematic insecticide to protect individual ash trees and trees in isolated infestations. The Canadian Forest Service developed the product in partnership with BioForest Technologies Inc. Now commercially available, TreeAzin is being used by numerous municipalities and landowners as one component of their emerald ash borer management strategy.
The issue comes down to cost; the treatment can cost up to a few hundred dollars per tree, and has to be repeated every two years for as long as the beetles remain in town.
As of yet, anyone in Ottawa willing to go this route has to pay the cost of saving a city tree himself. The Greenspace Alliance of Canada’s Capital, a not-for-profit corporation representing community members with concerns about conserving green space in Ottawa, points out that Oakville, Ontario launched an aggressive program in 2010 to save its ash trees by treating them with TreeAzin rather than cutting them down. The treatment, which costs $160 to $190 per tree and is good for two years, is far less than the City of Ottawa is paying to remove and dispose of a tree, estimated to be anywhere from $1,200 to $1,800.
Just one of the many ash tree-lined streets in our community
I asked City of Ottawa Ward 18 Councillor Peter Hume why Ottawa hasn’t followed Oakville’s lead. He tells me it comes down to scope. Hume says, “I wish we were like Oakville – they have 7500 ash Trees – we have 75,000 ash trees. But that said, we are treating about the same number that Oakville is with TreeAzin. Our problem is that we have so many trees some get infected and we don’t even know until it is too late – if a tree is more than 30% infected TreeAzin won’t save it so we want to treat the trees that are in the best condition to survive and then manage with the beetle.”
Awareness may be the most effective weapon in the fight against the Emerald Ash Borer. Infected trees start to show deterioration from the top down, so it’s important to monitor trees’ growth before it is too late. It will take a lot of vigilance and a fair amount of luck to slow down the pests before Ottawa’s ash population is lost.
All photos by Leah Walker