6

A few years a go, my neighbor had a large weed that was growing next to their house. By the next year, it was as tall as their house. Now several years later, it is no longer a hollow plant; instead it has some type of bark and is very sturdy.

Since this weed/tree is only 10 ft (3 m) from my fence line, its roots have offshoots that sprout in my garden and around my house every year. This year, I tried digging out one of the roots to one of these offshoots, and it took me all day to pull out a root clump the size of a basketball.

Here is one of the offshoots (on the right, next to fence) that I tried killing the year before. I left for the spring and when I came back in the summer, this is what was there.

How do I kill this offshoot at the root?

How do I stop this thing from invading my property every year?

Invasive weed plant from neighbors yard

Peter Mortensen
  • 143
  • 4
Spectrem
  • 161
  • 1
  • 4
  • 4
    I think you're doing all you can do, legally. You could try digging along the fence line down a foot or two and putting in a hard barrier (like a 0.25" steel plate) that the roots can't penetrate. But they may find a way under that. –  Jan 27 '23 at 00:58
  • There has to be a weed killer that I can pour to make the ground poisonous to this plant specifically... –  Jan 27 '23 at 01:04
  • 2
    Well, if you want to bother, you could likely take your neighbor to court to force them to contain it, rather than you having to keep it out, but that's not a question for here, being law. Nuisance plants and noxious weeds, etc... If it's on the correct local list of unwanted plants they might have to remove the whole thing. There's also the herbicide approach, for anything that shows up on your side of the fence. That goes on the foliage, not on the ground. – Ecnerwal Jan 27 '23 at 01:09
  • 6
    Have you discussed this with your neighbor? Maybe getting rid of the whole tree is something you can work together on. – gnicko Jan 27 '23 at 02:44
  • 8
    Since it's just one unobtrusive stem, Why not just chop it at ground level every year? That takes about 10 seconds and lasts for months w/o chemicals, liability, or interfering with your other plants. Or just let it grow and enjoy the grapes. – dandavis Jan 27 '23 at 02:50
  • 1
    @dadavis... My post says it grows AROUND my house and tends to create "root balls" which create even MORE offshoots. This isnt a 10 second job... the weed "trunks" grow very quickly and by the end of the summer, they are difficult to cut. Im not sure what you mean by grapes... there are no grapes... only spiny stems that make the property look like a junkyard. – Spectrem Jan 27 '23 at 03:42
  • 1
    @gnicko , The neighbor's house is a rental. As well, based upon the estimates I have received based upon one of my trees. It wont be cheap for them... This weed tree is now 12 ft tall or more... – Spectrem Jan 27 '23 at 04:39
  • 5
    12 feet is still easy to chop down; I've done it. Have the neighbor send their landlord a photo, tell them that it's an invasive nuisance, and ask if there is any good reason they shouldn't murder it Better to do this cooperatively if possible. – keshlam Jan 27 '23 at 05:42
  • 2
    Have you talked to the landlord at all? Does the landlord want this plant, or simply tolerate it? Do you have an otherwise good relationship with the landlord? – user3067860 Jan 27 '23 at 17:00
  • 1
    If you have already talked to your neighbour then I would accidentally spray it with roundup. It won't kill a tree, but it may help with the shoots popping up. – Rohit Gupta Jan 28 '23 at 01:41
  • 1
    If you don't insist on having lifeless grass land, you may as well plant things on your side that you like and which will overshadow anything trying to grow up past them. Nature doesn't like dead places, life tries to reach everywhere. Or you can get small herbivore to chew anything growing out the soil. But in general, you need to work hard to keep life away. – akostadinov Jan 29 '23 at 14:08

4 Answers4

14

In order to determine how best to control the tree, we need to identify it, if possible. I think I've identified your problem as a Paper Mulberry (Broussonetia papyrifera). It's native to China and hardy in your region; the leaves in your picture are young leaves - you may see differently shaped leaves on the 12 footer next door. The attached link gives us one confirmatory point and one useful point.

This helps confirm the ID: "The tree can be weedy and fast-growing, spreading aggressively by means of root suckers, but it can be pruned when dormant (late fall or early winter) to control growth"

And this provides a potentially useful tip: "it has a shallow root system"

The tree is considered an invasive species across much of the South; not sure about Texas, and when I looked at Texas A&M's site it was terribly unhelpful. If it is invasive in Texas, the landlord may be legally required to remove it (laws on this differ by state).

So, how to control it? You have two options: physical barrier or chemical control. As noted in another answer's comments, chemically treating it may kill the mother tree, which doesn't sound like it'll be a bad thing (especially now that we know what the tree is).

Physical Barrier

I know that this works with shallow-rooted trees and shrubs because I've done it myself. It's a lot of work, but it's one-time work that you'll never have to repeat, and it's permanent.

  1. Find aluminum flashing at a hardware store. I recommend at least an 8" height. While you're there, buy a tin-snip if you don't have one.
  2. Dig a V-trench along the fence-line, with the straight edge of the trench just below the fence. You'll have to dig the trench the height of the flashing minus one inch. Trench the entire length of the fence all at the same time.
  3. Starting in a corner, lay out about 6-8 feet of flashing (more if you have a helper) and begin burying it, a foot or two at a time. Continue until you've buried all of the flashing.

My entire backyard is protected from my neighbors' weeds at this point; this method has saved me countless hours of work and frustration because one of my neighbors has a weed-pit for a backyard, with three different nasty stoloniferous weeds.

There is a possible negative here, specific to the mulberry. There is a good chance that the tree will sprout on the neighbor's side of the fence when its roots hit the flashing, so you could wind up with an unintentional hedge there. Since these are trees that can reach 50' in height, this could become a larger issue and could certainly damage the fence.

Chemical Control

Ignore the posters who recommend RoundUp because it is ineffective on woody plants. The chemical to use is called Triclopyr and it's safer (for you) than RoundUp. It's usually sold as Stump and Brush Killer. Make sure you buy the concentrate, not the already-diluted product. The Ferti-lome brand that I linked to should have a brush inside the cap. It's easy to use - simply cut the stump or stumps to within 6" of the ground, then paint the top AND SIDES of the stumps with the chemical. The tree and all of its roots will die.

Easy, but not as much "fun" as burying the flashing. Not a permanent solution, though, as I expect the tree to return every year.

UPDATE

I forgot to add that you can cut the stump down to ground level a month or so after treating it, if you want to.

Jurp
  • 18,009
  • 1
  • 15
  • 36
  • 2
    To expand on the chemical control, Spike 80DF will definitely take care of that weed, just don't **under any circumstance** apply it to any Oak trees of sentimental importance! – Glen Yates Jan 27 '23 at 16:31
  • The _Picture This_ app agrees with your identification. – isherwood Jan 27 '23 at 19:27
  • Yeah, Roundup is nasty business. It's been implicated in leukemia. – Harper - Reinstate Monica Jan 27 '23 at 22:25
  • Note that Spike 80DF requires mixing with water prior to use, which can expose you to the chemical. It's a pasture/rangeland herbicide that kills woody plants via root intake (it's applied to the soil around the plant, not to the plant itself.). This may mean that it does not leach out of the soil quickly, so could be an issue near edible plants. Most importantly, note that it is labelled "not for residential use". – Jurp Jan 28 '23 at 16:10
  • Downvoted for recommending a pyridine herbicide. For gardening purposes, pyridines are not biodegradable. Pyridines contaminate vegetative matter, even after generations of composting. – Jasper Jan 28 '23 at 16:36
  • 1
    @Jasper. According to sources such as National Pesticide Information Center, triclopyr is broken down by microbes in the soil, with a half-life of 8-46 days. http://npic.orst.edu/factsheets/triclogen.pdf Since it requires about 1-2 tsp to kill a 6" caliper stump, the risks of it even reaching the soil are minimal. I am not recommending that it be used on vegetative matter, only on the stump, so there's no risk of contamination of compost. If you have a better solution, please post it. – Jurp Jan 28 '23 at 19:45
  • The plants in Dallas that I think are giant ragweed in Dallas TX parks grow very tall (over 8 ft) and can develop a 1" diameter very tough stem. Are you sure this is not possibly giant ragweed? Perhaps the OP could post more pictures showing the stems and the branching pattern. He says he is in the Dallas area so depending on where he is I would be willing to drive over for a look. Also I have used triclopyr on stumps of nuisance, volunteer trees like hackberries in my yard. I would be interested in what part of Dallas this property is in. I am in North Dallas near Preston and Beltline. – Jim Stewart Jan 28 '23 at 22:59
  • 1
    @JimStewart Yes, I'm positive that the plant isn't giant ragweed; they grow to the same heights here in Wisconsin and the leaves look more like dinosaur feet than those. As I noted, they're also much larger than the ones on the tree. The main ID point is that giant ragweed dies in the winter, regardless of hardiness zone - once it sets seed, it's done. One last point - the paper mulberry has two different shapes of leaves. Expand teh photo and look at the 9/10 o'clock position and you'll see the non-lobed version. – Jurp Jan 29 '23 at 00:37
3

We have a non-native invasive tree on our property line in various places. Cutting the trunk at the ground level is a very short term solution, as the plant grows like weeds. My research led me to believe a product such as RoundUp™ would work, but it only delayed the inevitable.

After that period, I read a suggestion to drill into the stump and pour undiluted RoundUp™ into the cavity. It has been more than a year and no sprouts have appeared. Adjacent growths that appear to be branching from the main trunk and are growing in a not-inconvenient direction seem to be living a normal life.

This would imply that the main body on the other side of the fence may not be affected, but that's not a certainty.

fred_dot_u
  • 131
  • 1
  • 1
    The stuff actually does work best applied to the foliage as directions indicate. Then the plant transports it to where it will do what it does. – Ecnerwal Jan 27 '23 at 01:59
  • A lot depends on the foliage (leaves). Roundup doesn't work on things like English Ivy because the leaves are too waxy for the herbicide to penetrate. For plants like that, I think they actually recommend cutting them back then applying Roundup to the exposed stems/stalks. –  Jan 27 '23 at 02:34
  • 2
    Be careful with this method, if it kills your neighbor's tree you could be held liable. – dandavis Jan 27 '23 at 02:40
  • 1
    RoundUp is very ineffective on woody plants and is only translocated within plants via the leaves. This method is expensive (because you'd need high-concentration product) and very unlikely to work. On all trees older than, say, a couple of years the center of the stump is already dead, with no xylem/phloem and thus no way for the chemical to be transported to the roots. People who anecdotally say this works are typically using it on easy-to-kill trees like conifers, which don't resprout from stumps anyway. – Jurp Jan 27 '23 at 13:41
  • @Jurp, that's how I understood the instructions on the package as well. Despite that aspect, my results based on an internet-discovered suggestion of drilling into the stump resulted in the incredibly-invasive/resistant tree ceasing to invade. This particular plant is some form of pepper tree and will re-sprout from the tiniest bit of living stock. – fred_dot_u Jan 28 '23 at 11:13
  • @fred_dot_u Did that pepper tree have a green trunk and/or pith? That could explain it. Was it a small-diameter stump? – Jurp Jan 28 '23 at 13:04
  • One tree trunk had various segments, once removed. The primary trunk was about 30 cm/12 in or larger in diameter, the other about half that. Multiple holes in different angles for the former, one hole for the latter. So much spidering of the visible roots that the entire mass could have been one organism and other "legs" are still green. Not sure if the trunk is green, I'm partly color blind. – fred_dot_u Jan 28 '23 at 22:25
  • Glyphosate concentrate applied to about a dozen freshly-cut 1" - 2 1/2" inch stumps of Ilex aquifolium (common holly), then covered with common plastic produce bag, resulted in 100% kill. Another win for Roundup. – kreemoweet Feb 02 '23 at 04:17
2

I believe this is Giant Ragweed. I have cut it down in a couple of Dallas parks that I do volunteer work at. If this is what you have, it is a native plant, not an exotic invasive.

I am generally not a fan of herbicides and even if I wanted to use one I would not be allowed to on public property. I have sometimes used the cord actuated pruning cutter on a tree pruner to cut these where there is also poison ivy. Otherwise I use loppers or even a pruning saw.

Jim Stewart
  • 145
  • 3
  • I am in the Dallas area. So this is very useful information. Thank you – Spectrem Jan 27 '23 at 03:44
  • 4
    Sorry, it's not giant ragweed. The lobes on the leaves are too close together and the leavbes themselves are too small. Giant Ragweed is also an annual, so would die over the winter even in Texas. – Jurp Jan 27 '23 at 12:48
  • 2
    Most likely, the tree is pper mulberry. See link in my answer. – Jurp Jan 27 '23 at 13:43
  • I suppose the general shape of the branching fits the paper mulberry rather than the Giant Ragweed? – Jim Stewart Jan 28 '23 at 22:41
0

We use all natural method, no poison.

Mix Vinegar with some soap (soap is to keep the vinegar on the leaves, so just a touch of it).

Spry on foliage and let it work for day or more.

Might have to repeat the process. That would stop the growth above ground but not the roots.

  • 1
    I've tried this too, but it doesn't really kill the weeds, it's about the same setback as weed whacking them. Vinegar takes about 5 or 6 treatments a season, compared to roundup which only takes 1 or 2. – dandavis Jan 27 '23 at 02:39
  • @dandavis roundup is known to cause cancer, vinegar will not do that –  Jan 27 '23 at 02:43
  • 2
    Certainly not in household use, don't worry. Tylenol will kill you given enough. The cases I've seen were landscape workers who mix gallons of concentrate weekly for years, often under time pressure. Wear gloves and a covid mask if you want to be 110% safe. Another conern with vinegar is that long-term, it can acidify the soil, which promotes moss, which robs good plants of rain and alters the microbial environment, which promotes more weeds... – dandavis Jan 27 '23 at 02:55
  • 3
    Roundup has been adjudicated as causing cancer; the science on whether it does or not is still not settled. Personally, I rarely use it, but I do still use it occasionally. Also, Bayer is removing RoundUp from the US retail market this year due to the ongoing lawsuits, so this will be a moot point in a year.. – Jurp Jan 27 '23 at 12:50
  • Is Roundup going to give you cancer if you don't get it on you? I follow the instructions carefully so I don't get it on me. – Don Branson Jan 28 '23 at 23:25
  • @DonBranson As far as I can tell, occasional residential use while taking proper precautions to avoid contact with the concentrated form of glyphosate is unlikely to harm you - but I am not a physician. RoundUp will still be widely available in the environment because it will be sprayed onto millions of acres of agricultural fields, as many forms of corn and soybeans are "RoundUp Ready", which means that they cannot be killed by it but weeds in the fields will be. Some weeds are already resistant, which is why we now have "dicamba ready" seeds for some crops. – Jurp Jan 29 '23 at 14:30
  • @Jurp Can you point me to something that indicates it stays in the environment, vs., say, breaking down into something harmless? – Don Branson Jan 29 '23 at 18:56
  • 1
    @DonBranson RoundUp? Well, there is a recent study showing 85% of people in the US have glyphosate in their urine, probably because we're eating it in our food. https://www.usnews.com/news/health-news/articles/2022-07-12/weed-killer-glyphosate-found-in-most-americans-urine. Glyphosate remains in soil for at least 6 months but then breaks down: "Glyphosate binds tightly to soil. It can persist in soil for up to 6 months depending on the climate and the type of soil it is in. Glyphosate is broken down by bacteria in the soil" see here: http://npic.orst.edu/factsheets/glyphogen.html#env – Jurp Jan 29 '23 at 20:27
  • 1
    @DonBranson - In case you care, I was a certified pesticide applicator in Wisconsin for 5 years. This involved taking a fairly detailed test about different products, means of application, means of disposal, protective equipment, etc. As a result, I NEVER use ANY pesticides in my vegetable garden. It's not always about the chemical, it's also what it breaks down into. I'm not positive that glyphosate breaks down into bacterial metabolic products; many "safe" herbicides break down into carcinogens, so better safe than sorry, IMO. – Jurp Jan 29 '23 at 20:35
  • @Jurp - I've heard it claimed that it breaks down as soon as it hits the soil, so I was hoping you have references like the ones you provided so I can hear both sides. Thanks! – Don Branson Jan 29 '23 at 21:16