The cost of not saving Ontario’s ash trees

By Mark Cullen, Ottawa Citizen September 6, 2012

If you could have saved the mature elm trees of Ottawa from the ravages of the Dutch elm disease, would you have done it?

If I offered you the chance to in-vest, say, $1,000 spread over six to eight years (approximately $150/year) in return for $2,000 to $3,000, would you be interested?

If I told you that the oxygen that we breathe every day and the shade that we seek on a hot summer day is at risk of being depleted by up to 10 per cent within the next three to five years and that much of this depletion is completely avoidable, would you be concerned? Would you want to know more?

Only one of these questions is hypothetical and that is the first one.

We lost virtually all of our American elm trees in Eastern Canada in the 1960s and 1970s. There was no risk-free preventive measure that could have been taken at the time that Dutch elm disease moved through our country.

This is not the case for the white, green and black ash trees that pepper the urban forest, line many of our streets and grace much of the private property. The tree canopy in the National Capital Region is made up of more than 20 per cent ash. There may a nice ash specimen in your yard.

The emerald ash borer is devastating the entire population of ash trees in Ontario. Within three to five years, it is predicted by people who know about these things, that all of our ash trees will be gone. Dead. Ready to be cut down and disposed of.

Ash trees have served us well as a hardwood tree that provides shelter for birds and other wildlife. They convert CO2 into oxygen in the growing season, and due to the fact that they leaf out later than most deciduous trees and drop earlier come autumn, they provide cooling shade in the heat of summer and gently filter warming sunshine into our lives in winter. They are clean, well-shaped landscape plants that are native to our area. No one could dislike an ash.

Unlike the American elm, the ash can be saved.

The popular garden/environ-mental writer and broadcaster Lorraine Johnson has a large 12-inch-caliper ash standing on the street at the front of her home. This past year she paid from her own pocket to have the tree treated with a biologic-al (read: safe) insect control called TreeAzin. It must be administered by a certified professional, not be-cause it is toxic to humans or pets, but it does require some training to administer the liquid by drilling in-to the tree trunk and injecting it with a rather sophisticated syringe.

The good news is that, if you choose to be proactive, you can likely save your ash tree from the emerald ash borer.

Based on Lorraine’s experience, you can expect to pay about $225 to $275 for one treatment for a mature ash with a caliper of 35 centimetres measured at 120 centimetres high (approximately chest height). The tree will need to be treated three to four times with TreeAzin: once every couple of years until the bug has moved on. It is predicted that it will move on after it devastates our ash tree population and runs out of food.

The upside of treatment is that you get to keep your ash tree. In return for your investment and trouble, you will not have to pay to remove the existing tree when it is dead (a savings of up to $3,000) and you will not have to replace it (saving up to $500). Not to mention that you will not have to wait 30 to 40 years for the new tree to mature.’

TreeAzin was developed in partnership with the Canadian Forest Service and the private company BioForest Technologies Inc. In the words of Paul Bolan, of Bio Forest: “TreeAzin has no adverse impact to the environment. The active ingredient is azadirachtin, a derivative of the neem tree in Asia.”

Bolan adds that the cost of Tree-Azin has been reduced by 30 per cent since it was introduced in 2008, and that with growing demand for the product, lower costs are anticipated in future.

It is refreshing to hear of a new product that goes down in price while demand increases, rather than the other way around.

The City of Ottawa has developed and implemented an aggressive ash-borer management strategy that promotes ash canopy preservation. While city council has no plans to preserve all ash trees on public land, it has recognized the financial and environmental benefits of preserving high-value, healthy ash trees.

We are fortunate in Ontario to have a choice: we can act to minimize the problem of the borer or we can ignore it and let it take its course.

While I admire Ottawa’s council for taking bold action to preserve mature ash trees on public land, I urge you to ask your councillor what, exactly, is being done to pre-serve our tree canopy. How many trees are being planted to replace the trees that will inevitably die? What with? What is the role of native trees in replacement?

As private landowners, we need to be looking in our backyards (and front yards) where ash trees may be established and worth saving. Per-haps you own an ash tree that would be cheaper to save than cut down. According to Dr. Sandy Smith, dean of forestry for the University of Toronto, this often is the case.

Consider the costs of replacing the tree and the time that it will take to make a measurably positive impact on your quality of life and your community.

It is my opinion that, when we no longer care about the health and wellness of our mature trees, our cities are on the slippery slope of decline. Our inaction has the making of urban decay, in earnest.

The cities of Cleveland and Detroit no longer have this choice – their ash trees are beyond saving. Take a drive and have a look.

Lorraine Johnson reminds you “buyer beware” when shopping for a professional applicator. There are some contractors who may take ad-vantage of this situation.

When asked what he would recommend, Bolan says: “In short, develop, implement and maintain an EAB management plan based on the most current science available. The study entitled Coalition for Urban Ash Tree Conservation is a good place to start.”

Here’s a few websites with more information on this issue:

  •   For more details on TreeAzin and a list of certified applicators, visit
  •   Ottawa’s injection program: http: // preservation/eab/injection/index. htm
  •  A look at where Ash trees are and the city’s management plan: http: // webottawa/documents/pdf/mdaw/ mta1/~edisp/cap106603.pdf
  •  How to identify an Ash tree and the borer: http: // env_water/tlg/trees/preservation/ eab/ash/index.html

Mark Cullen appears on Canada AM every Wednesday morning at 8:40. He is spokesman for Home Hardware Lawn and Garden. Sign up for his free monthly newsletter at

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