How to Kill Weed Trees

[Louise Waffles]

I have some invasive weed trees (trees of heaven, haha, so NOT) along a fence line that has been kind of neglected. I want to kill them and use the fence as a trellis to grow cucuzzi squash. Can I do it without chemicals? My birds free range along this property, but I need the trees gone to free up gardening space.

 

[Ridgerunner]

I’d never heard of that tree so I googled it. Man, what a pain. It’s extremely weedy, sprouting like crazy from the roots. It grows from seeds, I did not see how long they last in the environment. They like full sun and can do well in horrible soil conditions like a pH in the 4’s. The blooms stink. The tree (probably the roots) put out a chemical that kills other vegetation so it doesn’t have to compete with them. It’s one of the fastest growing trees around so it shades out what competition that chemical doesn’t kill.

I don’t think eradication will be a short-term effort without chemicals. From what I read I’m not sure even chemicals would kill it out quickly, I think you may need a season treating every sprout soon after it sprouts. Even then it could take a while and with that chemical that kills other plants the tree develops it may take the ground a while to cleanse itself so other things can grow.

How big is that area, especially root spread? I think it may be a multifaceted approach. If you dig it out, anywhere you put a root could start another tree since it grows from the roots so be careful how you dispose of them. Burning may be a good disposal option. I never get all the roots when I try that so you will still get sprouts. It will take real persistence, but if you remove those sprouts as soon as you see them, eventually the roots in the ground will die as they run out of nutrients to send up new sprouts. I don’t know if you can do that in one season or not with that tree.

Since the tree needs sunlight, maybe you could clear the area out and smother it in black plastic. Maybe the combination of heat under that black plastic from solar power and depriving the sprouts of sunlight will kill it out, but it has to be a solid cover, nothing can grow between the cracks.

You might try burning it out. Cut it down, pile a bunch of brush in there to make a really hot fire, and try to cook the roots. I don’t have much hope for this method. From what I read about the tree, it would probably thrive in a burned over area since it grows so fast it crowds out the competition. And the heat from that fire doesn’t go very deep into the ground.

You might try chatting with your local Master Gardeners for ideas about how to do it without chemicals. If I were to chat with them, I’d be asking which chemicals to use. That sounds like a real nasty tree in many ways.

 

[lazy gardener]

I have some invasive weed trees (trees of heaven, haha, so NOT) along a fence line that has been kind of neglected. I want to kill them and use the fence as a trellis to grow cucuzzi squash. Can I do it without chemicals? My birds free range along this property, but I need the trees gone to free up gardening space.

More information: are you urban? Rural? How much area does this tree cover? I wonder if it would be toxic to pigs or goats? If I were in a location where that would be an option, and if I could get hubby's blessing, that might be my first plan of attack. Otherwise, You are going to have to cut every single sprout, every single trunk, and dig out the roots. Once they are cut, don't let them have ground contact again. Is the fence a wire fence? Picket? Do you need to leave it in place, or can you remove it, even temporarily while you wage war? Is this tree toxic to skin contact? If it's as nasty as RR has found, you may not be able to burn it. It could be that the chemicals in the smoke could cause problems if inhaled. Call your county Ag. Extension for help with this one. If you stress that you want a non chemical treatment plan, they might be able to help you with that. Otherwise, they are just going to tell you to go buy a jug of heavy duty Round Up or some such, and apply it repeatedly. Be sure you keep the area around the invasion mowed frequently.

I found this article. https://greenshootsnews.wordpress.com/2014/01/28/killing-a-weed-tree-without-herbicide/

It presented some ideas that are definitely outside my paradigm. I think this guy just might have a good strategy for dealing with your invasion. Trim high, after the first flush of leaves, then remove all the leaves. The tree will respond by putting out a second flush of leaves. By leaving the trunk intact for your first battle, it encourages the tree to put more energy into leaves and branches on the remaining trunk, instead of sending out more suckers. In the mean time, cut any suckers that come up. When trying to destroy a woody plant, cut suckers below soil line, and pull up as much of the rhizome/stem under ground as you can get to. You might even put a super heavy weed barrier on the ground to occlude light and discourage new suckers. Perhaps use old carpet. It might take you 3 years to succeed by using natural methods. But, you should be able to use the area a bit by mulching with a complete weed barrier while you attack the top growth. You could then do some container gardening, or hay bale gardening on top of the mulch. the area could be useful, maybe even attractive while you continue your war!!!

 

[Louise Waffles]

@Ridgerunner Yea, this stuff is awful. Did not realize how bad until my whole garden just would not grow last year. It kept sprouting up all through it. I'm doing containers this year.
There is about a 15 feet of wire fenceline about 3 ft wide. I know it goes further but the chickens happily kill anything growing in their area. There is a huge mass of honeysuckle along the fence as well. Apparently THAT does okay with this tree.

@lazy gardener, I'm in a semi rural area, and oh, how I long for goats, but it's not in the cards....I hacked away at it last year, and it doesn't seem to cause any skin problems...

I really like the idea of blocking out light and container gardening on top. The area gets perfect sunlight. I'm thinking heavy plastic or carpet, mulch, and condition straw bales on top to plant some cucuzzi.
I wonder if I leave the trunk intact after cutting all limbs off, drill holes, and squirt some herbicide in, and then dig along the biggest roots and do the drill/squirt...would that be feasible? I can maybe throw organic out the window to kill this thing that wants to kill everything else. But just for this, you know? I can drill holes on the side of the trunks OUTSIDE the fence line so my flock can't reach, and do so during a no-rain-for-a-while period. Does that sound good, you think

 

[Birdy Buddy]

I have some privet and Ailanthus trees that I would like to get rid of too. I have heard if you drill holes into the stump and fill them with rock salt it will kill the suckers.

 

[Louise Waffles]

I just looked that up, it sounds like a good solution. Except for the part about me and power tools. I'm going to give it a shot. Also, I was just told to try salt and vinegar. Cheap stuff and won't hurt my flock!

 

[SilkiesForEver]

I have these at our place as well. Some of them have grown absolutely massive. I have no idea why they are called Tree of Heaven. I will have to give the rock salt method a try!

 

[Louise Waffles]

I have these at our place as well. Some of them have grown absolutely massive. I have no idea why they are called Tree of Heaven. I will have to give the rock salt method a try!

Haha, it's someone's sense of humor, I guess. Awful, AWFUL trees.

 

[lazy gardener]

@Ridgerunner Yea, this stuff is awful. Did not realize how bad until my whole garden just would not grow last year. It kept sprouting up all through it. I'm doing containers this year.
There is about a 15 feet of wire fenceline about 3 ft wide. I know it goes further but the chickens happily kill anything growing in their area. There is a huge mass of honeysuckle along the fence as well. Apparently THAT does okay with this tree.

@lazy gardener , I'm in a semi rural area, and oh, how I long for goats, but it's not in the cards....I hacked away at it last year, and it doesn't seem to cause any skin problems...

I really like the idea of blocking out light and container gardening on top. The area gets perfect sunlight. I'm thinking heavy plastic or carpet, mulch, and condition straw bales on top to plant some cucuzzi.
I wonder if I leave the trunk intact after cutting all limbs off, drill holes, and squirt some herbicide in, and then dig along the biggest roots and do the drill/squirt...would that be feasible? I can maybe throw organic out the window to kill this thing that wants to kill everything else. But just for this, you know? I can drill holes on the side of the trunks OUTSIDE the fence line so my flock can't reach, and do so during a no-rain-for-a-while period. Does that sound good, you think

It depends on what kind of herbicide you use. You might want to talk to your extension office just to be sure. I know that glyphosphate needs to come in contact with the leaves to be effective. And as far as using sale, be aware that it may poison the soil for a long time to come.

 

[Ridgerunner]

Glyphosphate, the active ingredient in Round-Up, only works on actively growing plants. I’ve tried it on some brushy plants and not had a much luck eliminating them. It will knock back the leaves and maybe even some of the limbs but does not do a good job of killing the roots for me. It works well on grasses, broad-leafed plants, and baby trees and brush but mature brush, small trees, poison ivy, and wild invasive briers keep coming back when I use it. I no longer waste spraying glyphosphate on brush or these invasive briars or poison ivy.

There are chemicals specially designed to work on trees/bushes. Some are used to spray the leaves. Others work best when you cut the tree and spray the stump. There are right ways and wrong ways to use these herbicides. Some are more harmful to the environment than others. Some last longer in the environment than others. There are application methods that can limit the danger to the environment more than other methods. Some persist in the ground for a long time so you should not eat anything growing there for a year or maybe more. One product that kills grass but not broadleaf plants that I use in flower beds does not get anywhere close to anything I might eat. It has a withdrawal period of a full year if used around nut trees.

I do not know which will work best on that specific tree. I do not know the best times and methods of application. I consider any herbicide, insecticide, mitecide, fungicide, or any of the other pesticides dangerous. I don’t care if they are manmade or natural, their purpose is to kill and they need to be handled with care. Some natural pesticides are so harmful to the environment (like rotenone) that they are banned by organic groups although they are natural. If you are going to go the herbicide route (which I probably would) I strongly suggest you do as LG suggested, talk to your county extension agent about it and learn what you can about what to use and how to handle it safely and effectively. Don’t depend on amateurs like me, talk to someone that knows what they are doing. To me, any pesticide is dangerous.