Tree-Of-Headache, or another tough invasive
- Timothy Arborist
- 5 hours ago
- 5 min read

Ailanthus altissima, commonly known as the Tree-of-Heaven, was introduced in the late-18th Century as an ornamental street tree. Well, that was a mistake. It spread aggressively- a fast growing, root suckering, partial-root-piece propagating nightmare.
As part of our 'remediate this totally neglected homestead' homestead project, we have a good 6000 square feet of Ailanthus. It was allowed to grow, and to root sucker, and to grow, until (now) it morphed into a single large Ailanthus mother tree and tens of her off shoots. It makes that piece of property useless for anything but Ailanthus, and Spotted Lantern Fly (which, go figure, loves Ailanthus), and that's about it. Our hope in remediating it is to not only remove the Ailanthus, but divide it into some 'chicken feed cropping' and extend our Walnut and Oak forests a long the west side of the property.
As I kind of hinted, controlling Ailanthus isn't like removing a pine tree. It will aggressively grow from cut stumps and new shoots, and the extensive root system is almost impossible to destroy mechanically as new shoots cut propogate from even small, leftover 'pieces'.
If we were to rely completely on mechanical methods, it would take years of physically cutting the sprouts in order to hopefully, eventually, reduce energy stores enough that finally the tree stopped.
That's a lot of seasons.
The Big Challenge of Ailanthus
Ailanthus altissima is notorious for its rapid growth and ability to sprout from roots and stumps. It produces a large number of seeds and can regenerate quickly after cutting. This makes it difficult to remove completely without a multi-step approach- relying just on mechanical means, or lazily, easily, ineffectively) just on chemical controls are not effective. You gotta hit it with a two-banger, and that is what we did.
Step 1: Hack and Squirt Treatment
Last summer, we took our first steps in getting the problem tree (and all her little tree-lings) under control and that was the hack and squirt method. So, axe in one hand, and 12.5% glyphosate-in-diesel in the other, we squeezed through the dense underbrush to blaze ( fancy, logging term for 'cut') and spray... (not so fancy) the herbicide into the exposed cambium. It is important not to 'girdle' the tree. Girdling meaning exposing the cambium ( the vascular layer below the bark (more or less)) completely around the tree. The problem with doing this is that it both shocks the tree (and, in the case of Ailanthus, causes an aggressive, Hydra-like growth along it's whole root system) and prevents adequate transport of herbicide into the root system.
By retaining bark, and timing the herbicide application in the late-Summer/Fall, we take advantage of the natural action whereby the tree is transporting photosynthate to the roots in order to build carbohydrate stores. In effect, the herbicide is a long for the ride, and gets transported into the root system where it can then go to work on killing the entire tree and root 'system'.
Why Hack and Squirt Works
It minimizes herbicide use by targeting only the tree
Reduces damage to surrounding plants
Effective on larger trees that are difficult to cut down immediately
How We Applied It
cMade angled cuts around the trunk about 6-12 inches apart
Injected a systemic herbicide into each cut
Treated all visible trees in the 6,000 square foot area
This treatment slowed the growth and weakened the trees. There was significant flagging by late-Fall, before leaf drop, where leaves had turned brown early, and then did not Fall.
Step 2: Cutting Down Smaller Trees in Winter
This Winter, we got about to cutting down the saplings. The lack of heavy foliage made the work easier, and we also took advantage of the cold weather to get rid of the mounds of old logs the previous owner had invited local tree companies to 'dump' on his property. Prior to removing the logs, it was difficult to navigate the area due to terrible footing, but as we removed more logs and then more trees, it became easier.
This was actually pretty easy work - mostly forestry mower (basically, an 80CC Stihl Weed Wacker with a steel head) or, for the larger 3-4" diameter trees, a chainsaw. We cut and burned the wood to remove as much woody debris and clean the area as much as possible.
Controversy # 1 Grinding the Stumps
I didn't have it in me to leave a bunch of 12" Ailanthus stumps sticking up. I know that grinding them down can possibly trigger the hydra-effect of regrowth along the root system, but I'm hoping that this will be mitigated by our Fall herbicide treatment. Frankly, I do not want a hundred 18" Ailanthus spars sticking out of the ground. It makes use of the land almost impossible.
So, by stump grinding the spars we are leaning into mechanical control. It will take photosynthate and our carbohydrate stores within the root system to 're-sprout' and by knocking it back we've created an energy deficit. Tree growth requires a positive balance in the energy trade, and the more you can effect a negative energy deficit on the tree, the more you are degrading it's ability to grow.
With the small stumps removed, we know have easier access to brush hog the area, and to observe, identify, and spray any re-sprouts. Reducing friction is a key part of controlling invasives over time- the easier it is to identify, to access the area, to mow or spray, the more likely we are to do the work required to reclaim this lost dirt.
Controversy#2 - The Mother Tree is Still Standing
Yeah, about that...
So, while I trust somewhat my timing and the concentration of glyphosate used in knocking back the Ailanthus problem, were I to cut down and grind the mother tree, I've basically eliminated any way of effective macro-dosing herbicide into the root system. It's like when the shredded Boo's door in Monster's Inc - once done, their ain't no going back.
( I know, Mike saves all the small pieces, but...)
I left the mother tree with the intention of using a Garlon 4A application next summer via a Basal Bark application. Research points to this herbicide being the more effective one for Ailanthus, and so I figure a bit of patience, another season, and another hit of woody plant eradicator can't hurt. With Invasive and Noxious Weeds, it's the long game that counts.
Trust me, next Winter, when I take that tree down, I will feel triumphant.
Where from Here...
Like I said 1, 2, 3 lines ago... with Invasive and Noxious Weeds, it's the long game that counts.
The key to controlling this area in the long term, like controlling any invasive weed, is to reduce the friction or difficulty of the work, and then follow up. After all the work in 'clearing the land' it is easy to get discouraged with the sheer amount of work still needed. However, there are some mental assists for keeping on things. Motivation in restoring or remediating land is very personal. My own thoughts on returning land to a natural, healthy state comes from Genesis 2:15
"And the Lord God took the Man and put him in the Garden of Eden to work it and take care of it."
If the big guy upstairs thinks it's important, then who am I to argue.
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