Xtremehorticulture

Removing 20-year-old Trumpet Vine Is Not Easy!

Q. I have 20 year old trumpet vines which I have been
trying to remove to establish a new garden. The vines have been dug out as best
as possible but as I try to establish a new garden I find shoots coming up from
roots so deep I simply cannot remove them. Is there a way to completely
eliminate the deepest roots from the trumpet vines without poisoning the ground?

Trumpet vine or trumpet creeper growing in someone’s property and draping over the wall

A. Trumpet vine is considered “invasive” in some parts of the country. This is usually in places where there is enough rainfall to support their growth without irrigation.Needs water to survive. It is very unlikely to survive in the hot Mojave Desert without irrigation. However it could become established along Lake Mead, the Colorado River, Virgin River, Warm Springs area and along desert washes.

Look here to check on it’s invasiveness

The only “organic” method of killing trumpet
vine roots is to totally cut off the top of the plant and force it to
“sprout” wherever it has spread underground. As this new growth
emerges, you will physically remove it with a shovel or hoe. By doing this
repeatedly and as soon as new growth emerges, you will eventually exhaust the
root system.
As you have already guessed, this will require a lot of
diligence on your part. My experience with plants such as these, exhausting the
root system by physically removing new growth can take you two to three years.
Another method is to leave the “mother plant”
and dig up suckers as they emerge. This helps direct the growth to the mother
plant and suppresses the development of sucker growth in new areas. The plant
will slowly “give up” growing into new areas as it ages.
There are chemicals that you can use to help you kill the
roots. None of them will contaminate the soil for any length of time. They ARE
chemicals so if these chemicals land on the soil surface there will be residue
left behind but it would be minimal.
If you are careful in applying these chemicals, none of
these need to reach the soil. This method relies on applying or dabbing an
herbicide on fresh cuts made to the plant. The plant is cut back and herbicides
are applied to these fresh cuts with a paintbrush. This technique relies on
herbicides to replace a shovel and a hoe.
Herbicides used for this include “dandelion killers” that
contain dicamba or triclopyr. You will have to look at the
ingredients on the label and the label should state that they can be used for
this purpose. The label may call them “dandelion killer”, “brush
killer”, etc. 
Roundup is also used for this job and applied in the same
manner. Follow the same dilution that is recommended on the label as a spray.
Repeat applications will be necessary because the plant will respond by sending
up new growth in different locations. So be prepared to follow up by cutting
back in growth and reapplying the chemicals.

24 thoughts on “Removing 20-year-old Trumpet Vine Is Not Easy!”

  1. Using the chemical/roundup method is killing a trumpet vine still a multi-year process? This summer I have started my fight against the previous owner's trumpet vine, and so far it feels like the trumpet vine is winning. I put 2,4-d or glyphosate on each new sucker, which promptly kills it, but within days I see new ones. I repeat this process on a weekly basis, but the suckers don't seem to slow down at all. I assume that eventually it will die, but will it really take 2-3 years, or are chemicals effective enough to speed up the process?

  2. It is difficult to say how long it will take. But it is very possible that this is a multi-year project. You are removing new growth and taking away food reserves stored in the roots. How extensive are the roots? How much food reserves are there? We don't know but we do know that well established trumpet vine will have an extensive root system. You can remove new growth with chemicals or manually but cutting them off when you see them. Both work. Roundup and 2,4-D are systemic so they will kill a bit lower into the soil than cutting them off. The best time to apply chemicals is in the fall a month before leaf drop. There is a natural movement of carbohydrates and food reserves going into the roots. The plant's first response after cutting or chemically cutting tops off is an explosion of growth in the area near where the damage happened. Normal. Then it "figures out" that this is a bad place to grow and will grow faster and stronger in the direction that is not threatened. This may be enough to slow new growth in the treated area or possibly eliminate it,,,,,over time. But the best way is to totally eliminate the plant and keep new growth cut or burned back.

  3. What I did was to start with the massive roots, using a shovel and a pickaxe, and map out the root system a bit. Then I sawed off the huge root, and found that I could lift it. I kept doing that and found that I could pull the large roots out fairly easily. It was the junction roots that gave me trouble. Those would sometimes stay near the top of the soil but at times would dive straight down such that even a 3-4 foot dig couldn't get them out. In those cases all I could do was break them off so that I could could continue peeling the surface roots. With smaller thinner roots still in the soil, I now plan to use Glyphosate on shoots and hopefully kill it. But we'll see.

  4. Roundup is not the best for killing woody plants like vines. and as you found out, if you miss any part of trumpet vine it will grow back. It can be very difficult to control. I would suggest you try any type of woody brush killer…these chemicals usually contain either Dicamba or Garlon (trichlopyr) and they are usually more effective on woody plants than glyphosate (roundup). Cut the vine back very low in the fall..immediately apply any of these chemicals at the label dilution to the open wound you created. Use a paint brush or anything to dab this concoction all over an open wound.

  5. I have had trumpet vines invading my boxwood bushes for 20 years; at first I thought I was okay with them, with their occasional bright red flowers. No more! Since ten years ago, I cut them out "completely" once or twice a year. They come right back with a vengeance. The roots are indeed 3-4 feet deep and entangled with the boxwood bushes.
    To be more aggressive, three years ago I started digging and pulling out all the roots I could. They came right back. Then I tried poison ivy killer on the vines–this was inconsequential. Then I got serious. I used both Bayer herbicide mixed with glyphosate and sprayed every shoot as soon as I could discover it–literally monitoring once every week. That has been going on since Fall of 2019. Now it is Fall 2020, and rarely does my weekly monitoring discover any new shoots. It feels so good to be finally winning the battle! Today, I found one from a blown-in seed and easily pulled it out completely.

  6. I have complete sympathy with everyone trying to remove/destroy their trumpet vine. I have spent 2 summers trying to remove the trumpet vine that came with my house. This year I tried digging it up. If I break off a piece of vine by mistake, that small piece (even just an inch) now starts regrowing. I'm chasing my tail. Spraying the vines with an herbicide specific to vines hasn't made a difference. I spray and respray again and again. I have had to remove my entire garden because watering brings the vines into my plants. My next plan is to spend 2021 digging up more vine, continue spraying the herbicide and then building raised beds that are heavily lined and yet allow drainage. I'm hoping this starts to bring an end to my nighmare. Thank you all for sharing your experiences, I have found no one believes me when I tell them how hard it is to remove this vine. Cheers!

  7. I also inherited a trumpet vine with the purchase of our home. At 5 years of age it has overtaken one mature live oak and moving towards another. It is impressively graceful as it drapes from the oak branches, but I have learned about the nightmare that will follow.

    Our yard is small and heavily wooded. How May I kill this before it invades my neighbors yards?

  8. cut the plant so that only stumps remain about ten inches from the soil. While the cut is fresh, paint on weed and bruch killer herbicide containing trichlopyr in the active ingredients as a chemical name. It is also called garlon as one of its trade names. The label directions will tell you how much to dilute it with water. Apply it within minutes after making the cut. Repeat painting it three times as soon as it dries. Best time to do it is in the fall about a month before the leaves drop. the chemical will not leak into the soil through the bark and hurt other plants. Alternatively you can drill or cut holes or slices into the trunk and apply through these as well.

  9. I have inherited a 6 year old trumpet vine with the recent purchase of our home. Our 1/3rd of an acre home in San Antonio Texas is heavily wooded and our neighbors are fairly close. I would like to roll up my sleeves and try to take on the battle of trying to kill this hopefully before it invades my neighbors yards if it hasn’t already. Any advise on how to start? I’m shying away from painting chemicals on the freshly cut vine as I’m not sure it would affect my trees.

  10. As you have found out, trumpet vine can be very invasive and difficult to control once it gets established. I would suggest you strongly consider using a weed killer I am suggesting if you want to kill and get rid of this plant. If this weed killer is applied correctly, it will not bother the other plants in your yard.

    Roundup is not the best choice for this but it can work. The active ingredients of the weed killer you will use should be either triclopyr (Garlon) or dicamba (Banvel). Check the label on the brush control weed killer you buy. They are deathly on wood plants. Cut off the stems or trunks close to the soil this time of year and paint or spray the fresh cut with the diluted form of whatever product you are using and follow the directions for diluting to the proper dosage. Repeat the application in ten minutes or as soon as the cut is dry again. Don’t apply these chemicals to the soil or it can have long lasting effects on what you can plant there.

  11. My daughter just bought a house in NJ that has trumpet vine on a trellis. Beautiful flowers but my wife has already had contact with the plant and gotten a terrible rash from it. Before my grandkids touch it can I start to "do battle" with it now or do I need to wait until later in the fall?

  12. I had not heard of that before so I "googled" it. https://www.newportthisweek.com/articles/the-blare-of-the-trumpet-vine/#:~:text=There%20is%20a%20chemical%20in,and%20the%20coldest%20of%20winters at least at this source it says in some people with sensitive skin it can cause a rash. Usually the best time to start working on its removal is in the fall as weather cools off from the heat of summer but the plant has not yet gone dormant for the winter (lost its leaves). Any of those chemicals I mentioned before (usually its called some sort of "brush killer" or a weed killer that is for killing woody plants will work. The ingredients should contain trichlopyr or dicamba. Cut the vine, apply this chemical as the label tells you and do it to the fresh cut. It wont get all of it but will get most of it. Then either spray the new suckers next spring as soon as you see them. And do it again as soon as you see them. This will shorten the time you will need to kill it instead of whacking off new growth when you start to see it. Basically starving the roots out. Both work. It just takes longer without the weed killer.

  13. Thanks for the confirmation of approach – cut the stump and then paint on the "brush killer" to the cut. I can tell you, my wife's skin irritation is worse that any poison ivy I have ever gotten (or seen).

  14. Just make sure if you paint on a weed killer to make sure the cut is fresh when you do it or it wont work as well. Sorry to hear about the pain she had to endure.

  15. We cut down our inherited trumpet vine 3 seasons ago that was maybe 15-20 years old. Cut it down, dug out the mother plant and some roots. The problem is the suckers. They are everywhere, even after diligently removing them with weed removal tool (looks like a long screwdriver). I have dug up sections of roots in a 25-30 ft radius from the original plant, but suckers still come up. I'd say on average we're still pulling 10-50 a day, sometimes more when it gets abnormally hot.

    Life "gets in the way" and doesn't always allow us to spend 15 minutes in the yard on our knees looking for new suckers to pull out. Sometimes it might be a few days or even a week until we can get out there, but it is a daily ritual most of the time. Last summer we went away for a week and came back to some 170 suckers that we dug out. Are the suckers replenishing the roots energy through photosynthesis in this short time, or are we still slowly killing it despite the suckers getting sunlight? Sometimes I think these suckers have kept us at net neutral in killing it off despite our efforts.

    A second question is on the use of herbicides as we are considering them to aid in the battle. Should we spray the new suckers (1-2 inches tall) as soon as we see them, then just let the chemicals do their thing? I am afraid if we go that route, there will be hundreds of suckers in the yard in due time.

  16. I am only guessing but the best information I have found says the suckers need to be killed or sprayed a few days after they first appear. You might be right. You might be at net neutral regarding the photosynthates. I dont really know. The best thing I can tell you is that some research has been done on nutgrass control by "starving" the roots (killing the top back) when it is no more than the four leaf stage. So I am guessing the more you can stay on top of it, the better. I would guess that weekly sucker removal (or sprays which is the same thing but using chemicals to burn the top back) is often enough, not daily. You should see some headway (sucers will be decreasing showing you are winning) in about two months of staying on top of it. But the longer you let the suckers go, the more they will send photosynthates into storage. I guess that is why they say control has to be "religious"…not just Easter and Christmas. Regarding the chemicals… paint it on when the cuts are fresh and wet. If spraying, then use a surfactant (either buy a wetting agent or make one from 1 tbs liquid detergent per gallon of finished spray) to make sure the chemical makes it inside the leaves and doesn't just bead up and run down the leaf.

  17. Thanks for the reply. Great information on this website even though I'm near the great lakes.

    After fighting this war almost daily for the past 3 seasons, yes, there has been some headway but progress is hard to measure. Three or four days will pass and I'll be thinking we're getting ahead of it when we're only digging out 10 a day. Then along comes an abnormal heat wave and we're pulling 50 daily for a few days. There does seem to be more of the "weak" suckers as time has gone by (like a maple seed sprouting) as opposed to ones with good thick stems and a strong connection to the root. I would think that might be a sign that some parts of the root system are running out of gas.

    I have read that cutting the lawn weekly will prevent new growth, but in my experience if you don't dig it out of the ground, the stem will continue to sprout leaves. We pull most suckers before the leaves can grow more than 1/8 to 1/4 inch. The only time the suckers have ever been able to get taller than 1-2 inches is when we miss one hidden in the hostas or we are away on a trip. In that case some can be 6-9 inches, but that is rare and only if left for a week. So, yeah I'd say it's religious (edging on obsessive) in fighting this plant. (The roots did get into backyard drain tile so we have a motivation to beat it.) I would also think weekly sucker digging should be adequate and that the photosynthesis produced from suckers is negligible when compared to what it once was. (It was similar to the picture you have above.)

    I hope to post back some day with a success story. The month of June seems to be a "tell" in that it really goes bananas for two weeks as it wakes from winter slumber.

    If you can believe it, we did successfully kill a wisteria (also inherited with the house) without any chemicals years ago. A master gardener at the time told us to just keep digging out the shoots as deep as we could (weed removal tool). We never dug out the root system. It suckered for a good 10 years but they were confined to a 3-5 foot radius from the plant making it more manageable. It was overgrown and managed to collapse half our old purgula. After 3 years the suckers only popped up every couple weeks, so I do know there is hope against the trumpet vine.

  18. Yes there can be some information you can use if you live close to the Great Lakes but it is intended for the Mojave Desert dwellers. Trumpet vine is a lot harder to get rid of then wisteria. Trumpet vine is much more tenacious as you have found out. The weed killers to use are really meant for convenience more so than effectiveness. Except for systemic like Roundup that can travel inside the plant a short distance from where you apply it. Roundup or glyphosate as long as it's diluted to the proper concentration, usually no more than 4% dilution for the strongest rate, whenever you apply chemicals full strength that are meant to be diluted it doesn't work well. But I would encourage you you just keep the suckers cut back and you will see it start to weaken in about 2 months if it's strongly established.

  19. RE: flame weeder; yeah that's out of the question. It would be "burning down the barn to kill a few rats", and actually would probably burn down the house too. 90% of the suckers are on the lawn mixed in with the grass near the house. 10% are in the bordering garden and those are easy to miss because you can't even see them until they grow out of the hosta plants.

    Progress in two months… we dug up the plant three years ago and have been digging up shoots ever since on a consistent basis. I would say in looking back that the first year was the worst with the suckers. I *think* it's gotten better, but it's still a job for only the dedicated.

    For reference, we had some 35 suckers to dig up two days ago, then dug up another 30 or so today. The first summer after digging it out in early spring there were something like 150 suckers in a 20 foot radius after three days. Fast forward to this year (3rd year) and we had 50-60 after coming home from being away for three days in early summer. So, it's slow, but there does appear to be progress.

    The radius has also expanded this year and there seems to be more suckering on the outskirts than the center where the plant once stood. There definitely are times of the year when it goes crazy with suckers when it is abnormally hot temps. Before we cut it down, it was the very hot summers that the thing went crazy with flowers.

    The chemicals don't seem too effective and I doubt anyone has eradicated this plant with roundup or glyphosate. Plus the safety aspect with chemicals is too often overlooked. Last week I saw a lawn sprayed by a "green lawn" company and the guy had on rubber boots and a gas mask. We have only sprayed a few that popped in concrete cracks with dicamba herbicide. The spray killed it after three days, but the shoots do come back a few feet away weeks later.

    It might take a few more years, but we'll continue to vigilantly dig up those suckers. I do hope to provide a victory update some day.

  20. Could I pound copper pennies, tubing or wiring into the big sections of the root to kill it like a tree? I've been fighting the Trumpet Vine on and off for 16 years at my house. I've done the boiling water, chemical killer after cutting it, rotor tilling it, chopping roots out with an axe, etc.

  21. RE/Update: "We cut down our inherited trumpet vine 3 seasons ago that was maybe 15-20 years old." We managed to eradicate it after a little more than three seasons.

    A little over three years of digging up suckers did the trick. You can miss a day or two, but that's it. You have to be out there every day you're home digging out the suckers as deep as you can – sometimes twice a day. If you can find a root, dig it out, it will help. We didn't use chemicals even though I inquired about them here in the comments. Just old fashioned digging. As the comments state, it was sometimes 10-50 a day. We've only had 15-20 the past six months and they all were very weak, unlike the stronger little stems when it was going crazy. I'm sure there will be periodic suckers, but this is nothing even close to what the past three years were like. Last year I did clean out one of our drainage pipes where a root had intruded. That was our greatest worry, that it would clog up our drain pipes and cause bigger issues.

    Simply put you need to be vigilant. Don't use chemicals because you'll only ruin the land. Don't listen to people online who say you need a chicken in your backyard to get rid of this thing. It can be defeated as long as you keep digging out suckers robbing it of sunlight.

Leave a Comment

Your email address will not be published. Required fields are marked *