Hello friends and colleagues!

Here is our quarterly update of exciting events and activities that we have been up to….

Watch our TVOKids show – Secrets of the Forest “Tree Doctors”

We were so pleased to be a part of the TVOKids’ show Secrets of the Forest. The episode featuring Kyle McLoughlin is titled “Tree Doctors” and aired on September 9th. Secrets of the Forest is a nature-science series for kids that puts our Earth’s precious forests in the spotlight. Join host Taviss and Canada’s top scientists and conservationists, as they adventure across the country to get to the bottom of the forest’s many mysteries.

You can watch the 11 minute episode on TVOKid’s YouTube channel at this link: Tree Doctors

CBC Radio Appearances

Kyle has been dubbed the “Resident Tree Expert” on CBC Radio’s Fresh Air program. His appearances for tree health call-in segments have become so popular that he has been moved to a monthly segment. If you missed his appearance on July 27th, you can listen here: CBC Call In with Kyle on July 27

Kyle’s next segment is coming up quickly at 8:30 am on Saturday October 5, 2024. We also have a possible segment on Saturday, November 30 at 8:30 am.

Upcoming Workshops & Events

We have updated our website’s Events page to reflect our current offerings. We are open for scheduling professional development workshops and seminars starting in the spring, as well as events for the general public who are interested in trees, fungi and horticulture, including garden groups and naturalist’s clubs. Please get in touch if you would like to explore options for your group or workplace.

Ironwood Quarterly’s Question of the Quarter (IQQQ) – Invasive Tree of heaven Removal

Question:
An invasive Tree-of-Heaven growing inside a chain-link fence, about 1.5″ in diameter. Roots inaccessible because of location inside the fence. Based on what I’ve read triclopyr/concentrated glyphosate are considered the “only” ways to ensure the tree is totally dead, but these are essentially banned here in Ontario. The City of Hamilton’s Forestry department recommended Stump-Out (sodium metabisulfite) but that also seems to be impossible to find. What alternatives would you recommend? I would prefer not to resort to more extreme chemicals if possible but I also want to ensure that this tree doesn’t swarm across the yard after being cut, so any and all advice you could provide would be most helpful.

Answer:
When it comes to removing Tree-of-Heaven (Ailanthus altissima) you’re smart to remove it as soon as you identify it. Tree-of-Heaven is listed as an invasive species in Ontario and has an aggressive rooting habit that causes a lot of problems. I’ve seen some interesting situations in downtown Hamilton where Tree-of-Heaven has grown in locations that you would never expect a tree to grow, and the resulting damage can be expensive.

Getting rid of one of these trees (especially a small one) is best done with an Integrated Pest Management approach that involves consistency, physical controls like removal, and a chemical control to discourage regrowth. You are right to expect suckers – the root system will undoubtedly send out suckers as soon as it recognizes the tree above ground has been removed. While it’s tempting to look for a quick solution that is also cost effective, it’s important to remember they rarely exist when it comes to plants. Once you remove the main tree, plan to battle suckers and plan to do it by both removing them and by spraying a follow up chemical.

Chemical control of a pest species like Tree-of-Heaven can be tricky – Triclopyr (AKA Garlon) and Glyphosate (AKA Roundup) are widely considered the best in the industry and are generally considered to be low impact. While I believe Glyphosate has some significant issues in regards to ecosystem impacts and human health, there is no denying its effectiveness in controlling unwanted plants. What I suggest here is to consider applying Garlon to the cut stump in order to kill the remaining root system. If you’d like to take a less risky approach, consider using a solution of white vinegar, soap, and salt, as combined they will stress any suckers or remaining vegetation – though this will be far less effective than either Triclopyr or Glyphosate. If you are hiring a professional to spray these stumps, make sure they are certified/registered under the Ontario Ministry of Environment as Pesticide Applicators/Exterminators.

So, to cap it off in several steps:

1. Physical Control – Remove the existing tree – consider drilling holes into any part of the stump that you can’t remove completely, as the drilled holes will reduce the likelihood of resprouting.
2. Chemical Control – Spray the stump with any of the chemicals mentioned above.
3. Repeat steps 1 and 2 for any suckers that come up next spring.
4. Optional Cultural Control – If in a location where there’s sufficient planting area, plant a desirable tree species that will outcompete any Tree-of-Heaven suckers.