Crooked River Farm has several patches of the dreaded Ailanthus tree, also known as Paradise Tree, Tree of Heaven, or locally called Shumace.
Ailanthus is one of the most dangerous trees in VA. Where it sprouts up, it sets out it’s own natural herbicide that keeps anything else much from coming up except itself. Female trees set tens of thousands of seeds each year, and it readily sprouts from its roots. Cut down an Ailanthus, and you’ll have hundreds of new trees sprout from the roots. So it needs special treatment to eradicate. It now lines our roadways all over VA as well as the edges of forests. VA Tech researchers have been working on biological control agents for several years to no avail.
There are no organic control/eradication techniques for Ailanthus, so here we parted from our organic approach and resorted to limited use of herbicide.
The common recommendation for Ailanthus eradication is to spray the leaves with herbicide. This of course is a bad idea, as there is no way to prevent the herbicide from drifting onto other plants. A common technique of killing undesirable trees and shrubs is to cut off the plant, and paint the stump with herbicide, but Ailanthus foils this technique by immediately sending up sprouts from the roots that don’t die after the host is killed.
So we tried a different technique. What we did was hack into the bark of the trunk with a machete (a hatchet will do) around the tree to expose the cambium layer and create a pocket for the herbicide. If you girdle the tree completely it will sprout from the roots and you’ll create a bigger problem, so the trick is to leave about 1″ of intact bark and cambium in between the hacks. Generally, you do one hack for every inch of tree diameter. And then in each hack, you squirt the herbicide to the point just before it will spill out of the hack. For sprouts less than 1″ in diameter, we’ve had 100% success with just exposing the cambium with a scrape and then squirting the scrape. The Ailanthus thinks it’s still alive while it absorbs the herbicide, and by the time it realizes it’s dying and tries to send up root sprouts, it’s too late.
This must be done while the tree is actively growing or it won’t work. This means from the time of first leaf-set up until the females are flowering. We “treated” trees after flowering, and they seemed to respond much more slowly and will have to wait until spring to see if they have been killed or not.
We just bought a very small hand-held spray/mister bottle at the local garden shop and used Triclopyr herbicide, sold under various brand names. We did not dilute the Triclopyr.
Ailanthus Patch
Ailanthus patch after poison and BullHog
So far at least, it appears to work. The larger the tree, the longer it takes for it to die. One-inch trees will be bare of leaves in 4-6 weeks, 3-4 inch trees seem to take 8 weeks or so, and larger trees even longer.
And the work is fast – with a machete in one hand and the squirt bottle in the left, you can kill one of these nasty buggers in well under a minute. Just this summer, Trish and I killed acres of this “Tree from Hell” and just have some clean-up work to do in the 2009 growing season.
Dying Ailanthus
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March 5, 2009 at 11:09 pm
Jeff
I think you are over-doing it by not diluting the triclopyr. I used it some years ago to kill invasive exotics on my property and found that 10% worked fine on most everything. There were two species that required 20%, though. Also, be very, very careful with this herbicide – it can be absorbed through the skin and causes dizziness and nausea if that happens. Also, because it is mixed with an aromatic petroleum distillate (Penevator), you can breathe the fumes, to a most detrimental effect. I would urge the applicator to wear a respirator when using this very toxic herbicide. It is also not necessary to cut into the cambium – the Penevator will carry it into the tissue. Just spray it at the base of the trunk and then wait for the tree to die.
March 6, 2009 at 5:18 am
Crooked River
Jeff – thank you so much for posting. You bring up some very interesting and valuable points for those dealing with “Tree from Hell”, and herbicides both in general and specific.
I don’t think I was overdoing it by using it undiluted – the product I was using was already diluted. And I’m lazy by trade (engineer)
I should have been more specific when saying Trichlopyr, as it comes in many different formulations. Some (not the product I was using) are specifically formulated for basal bark applications, the technique you describe. The basal bark application is said to work well on smaller trees at certain times of year (with the proper formulation, which it sounds like you had). I don’t like spraying due to the collateral damage, and I chose the cut and squirt technique also because it was what seemed to work best in the summer, when I was at it. But your approach is perfectly valid on Ailanthus from what I’ve read, and thanks for sharing. And major kudos to you for working on getting rid of your invasive exotics.
And I hate using herbicides at all – but it is clearly the only way of dealing with Ailanthus. Although we were not spraying, and had no direct contact with the herbicide, we did use rubber gloves and (sometimes) respirators when applying. And, like you, I encourage anyone dealing with herbicides to know just what you are dealing with and take extraordinary precautions.
Although just a starting point, here is the best web page I found on getting started on the various means of Ailanthus eradication:
http://www.nps.gov/plants/alien/fact/aial1.htm
Again, thanks for sharing, and bringing up some good points, Jeff. What started out as just an experiment to see what this blogging thing was all about and share what we were doing with family and a couple of close friends has turned into something that gets dozen of hits per day, many with the search term “ailanthus eradication”, “multiflora rose”, “forest restoration”, “pasture restoration”. So would love to see more discussion of some of the topics here that aren’t really discussed effectively much elsewhere.
October 28, 2009 at 12:28 am
Alan
I want to add my thanks for this blog and the information sharing. Specifically the information on Ailanthus eradication. I work on projects here in California where the tree has become a real problem. We have had the problems you have describe with re-sprouting and doing so quickly after one is cut down.
I will try the methods you have described and let you know how it goes!
September 8, 2011 at 3:31 pm
cindy
I have about 100 ailanthus I treated this summer using hack-n-squirt. The leaves eventually turned brown (in some cases after multiple treatments) but in noticed that when I scrape the bark on some of the trees the layer underneath still looks green and healthy.
Is this normal?
September 8, 2011 at 8:22 pm
CrookedRiver
Cindy – that is unusual in my limited experience. Usually the opposite happens for me – I’ll still have some leaves on the tree-from-hell, but when I hack and squirt again, it seems like the tree is already dead, with the bark starting to peel off, and the underlying wood dry and even starting to rot. That being said, if you treated fairly recently (late in the season), it will kill the leaves but not the tree, it seems. So don’t cut any of them down yet! Wait and see what they look like come spring is my recommendation.
March 6, 2009 at 1:07 pm
Jeff
Chris – and I should have been more specific in regards to the product that I used. It was Garlon-4 and you are correct – it is formulated to be used as a basal bark application mixed with Penevator. Down here in Florida, Garlon-4 works well at any time of the year, but I would imagine that it should only be used during the growing season in Virginia. I purchased pure Garlon-4 from an agricultural chemical supply house and mixed it at a 10% rate with Penevator, which is colored red and is similar to a light machine oil. There are diluted solutions of Triclopyr available on the market (Pathfinder being one of them), but since I had a large number of trees to kill, I elected to go with the undiluted product, as using the diluted solution is rather expensive. I believe Pathfinder is a 10% dilution of Triclopyr and there are probably other brand names available also.
One other tip: RoundUp Pro mixed at a 10% strength will kill a lot of brushy species and even some trees. I had a very prolific vine (Gold Coast Jasmine) that I cut down to about 2′ high with a commercial hedge trimmer and then waited until there was a flush of new growth. Then, I sprayed the 10% RoundUp Pro solution on the new growth and that was the end of those plants! I imagine such a strategy would work on multiflora rose also, but I haven’t had the opportunity to try it out yet. I wouldn’t use a hedge trimmer on multiflora rose, though – I’d let John come in and knock it down with his Bull Hog first. Cutting the plant down and waiting for the flush of new growth avoids the problem of overspray which endangers other plants in the area.
I don’t like to use herbicides either, but in some cases, spraying really is the only practical solution available. All herbicides must be used carefully and wisely by an experienced applicator.
October 28, 2009 at 12:54 am
Crooked River
Thought I should give an update on the Ailanthus eradication program as there are people who hit this page daily searching for information on Ailanthus eradication.
This spring, many, if not most, of the larger (8″ or larger in diameter) Ailanthus were severely distressed (but not completely killed) by the hack-and-squirt treatment in the fall. So I went with the basal bark treatment on them. I bought Garlon, and diluted it 5:1 with diesel fuel. I sprayed it liberally around the bottom 18″ or so of those trees, and within a month there wasn’t a leaf hanging on any of them. I’m still going to wait until next spring to cut them down, though, to make *sure* they’re dead!
This spring there were a few patches where the Ailanthus sprung up as thick as a carpet. This was where others had cut down trees the previous spring not knowing what they were. With these, I took a small squirt bottle with a 10% solution of triclopyr and spot sprayed each and every little one. They came up in about 3 cycles before giving up the ghost for good.
We’ve gone from about a thousand of these trees to now just two small patches of about 100 or so total, which I’ll get next year. Some, of course, will continue to sprout up from seeds, so I’ll have to keep an eye out, but the problem is just about licked, methinks.
April 28, 2010 at 12:20 pm
elency
A neighbor just cut down a massive alianthus and we have a carpet spreading through out organic (and child romped) fruit orchard and garden, not to mention the two and three year old volunteers that lace our small property. Everything i’ve read says herbicides are the only way to go, but I was curious if you know, of the products you’ve used if there are any that are more safe than others? it seems like there just has to be some better way to get rid of these horrible, growth stunting trees . . .
April 28, 2010 at 10:27 pm
CrookedRiver
Elency –
Oh, man , I feel your pain. I can’t hardly imagine anything worse with ailanthus than it sprouting up in a vegetable garden or orchard, as as far as I can tell herbicides are the only way to effectively deal with this menace. And I wouldn’t want to spray this stuff where my children play or where I plan to eat, eat either. My ailanthus are all out in the woods where there is (I hope!) minimal impact of using the chemicals relative to the SERIOUS negative impact on the environment of these trees taking over.
I wish I could help ya, but we’ve been using very limited spot use of the herbicide triclopyr, and I don’t know how it moves in food production sites. But my experience with other invasive exotics is that if you mow them enough, they eventually give up and die. It might take 3 or 4 mowings per year, for only a year or two, but you might be able to get rid of them in just a year or two in mowing.
This page gets a lot of hits every day with folks looking to how to deal with this menace. Please post back with any findings and experiences you have….
Best Regards -
August 6, 2010 at 10:19 am
Dusten
Just wanted to say thanks for sharing your story and Ailanthus removal methods. The link to http://www.nps.gov/plants/alien/fact/aial1.htm was especially helpful. I live in North Denver and these plants are a real problem, there are many that are 50+ feet tall, including a cluster of 3 in my backyard. I picked up some Triclopyr last night and did the hack and squirt method on the big trees and several smaller (under 4″ diameter) plants. I’m happy to report that the smaller trees are weepy this morning, clearly the poison is working. I’m sure the larger trees will take considerably longer to uptake and show signs of poisoning. I will let you know how things turn out. One question: Did you need to hack and squirt all trees, or did you find that after the “mothers” started to die, the root suckers did too?
August 6, 2010 at 2:40 pm
CrookedRiver
Dusten – unfortunately, you have to hack and squirt *all* of the suckers. The small ones, I just do a foliar application. It’s a chore – I’m now on my third year of working them off the farm.
April 24, 2011 at 5:02 pm
the optimist
I have had a grove of these trees in the back pasture. My method has been to cut them down to the ground so that I can mow over them repeatedly (3 times a year or so). It does seem to control them to some degree. If you stopped mowing, I’m sure they’d come back, but this seems to be a low tech solution. The same works for bamboo, if you can get it while it’s young and tender.
July 31, 2011 at 2:43 pm
Ken
I tried your method with “Crossbow” which has the right ingredients. I used it in June and looked it over today (just got back from vacation). Some of the Ailunthus look like it killed them completely, some have some wiltiing but look to have survived and some of them look like they are perfectly healthy. I’m guessing maybe 10-15% were killed. I think I got complete kill on the mulberry trees I used it on. I would have thought that I would get better results. I think I got plenty of the stuff in the cut. Maybe I need to cut more or spray more on. I don’t know? Would it help to get to it a little earlier next year?
July 31, 2011 at 5:06 pm
CrookedRiver
Yes, Crossbow is the right product. I’ve not had 100% success at first “squirt”, either, Ken, but 10-15% is awfully low. June should be early enough, so that shouldn’t be the problem. You say you got plenty in the “cut” – you do mean “cuts”,don’t you? On any tree bigger than 1″ or so in diameter, you need to make multiple cuts. Otherwise,all I can suggest is that you hit them again. But do it soon, as my experience is that it is getting late for “treating” the ailanthus.
May 21, 2012 at 10:24 am
Terry
This tree sucks…I have a huge one in my front yard and a fairly large one in the back yard, however the one in the back yard is not taking control of my yard (probably because of the huge old oak trees) but the one in the front is taking over my yard and the neighbors. I would like more input on this subject