We have loads of bitterroot that grows along the fenceline of a nearby park. The parks dept. does not have the resources for invasives mitigation and just hits it with a string trimmer. But inevitably it grows big enough to shrug it off and then it gets bushy.

I try to prune it all once a year, but I'm considering using glyphosate this year. The problem is there are trees within 15' of where the bitterroot is rooted, and this being a canopy-starved city I'm much more concerned with protecting the trees than I am with fighting this dumb vine.

So my question is, is a foliar application of glyphosate any risk at all to any of the nearby trees (liriodendron, white oak, baldcypress, london plane, sweet gum)? If it is, I'd rather just hack it back until it starves for light. But if not, I'll go with the blue stuff.

E: lol, Bittersweet, sorry.

Looking to get my facts straight about how this plant grows. We have some in the hood and I saw that someone mowed through it. Would bits of the shrapnel from that be a regrowth risk?

I have a Tree of Heaven growing outside my house. It’s about 8’ tall and maybe 1-2” diameter trunk. I was waiting for cooler weather to deal with it using the hack and squirt method or basal bark method with triclopyr, but in that time it apparently it’s roots hit a sewer drain pipe from the house that now needs repair. Now I’m in the dilemma of wanting to kill it the correct way so it doesn’t spread, but also kill and remove it quickly so we can dig under it to replace the pipe. Not sure how I should approach this, just use the triclopyr wait two weeks and dig up as needed hoping it’s been able to take full effect?

Living in a place spotted lanternflies are abundant and invasive, I’ve upcycled their wings into an acrylic painting sealed in resin. 6x6” canvas, it’s part of a triptych of lanternfly art and someone liked it enough to buy it leaving me with 2 other pieces. The trees I sourced them from no longer have lanternflies this year!

Just wanted to vent a bit. I bought a house and the side and back hedges are all buckthorn. A few trees in the back are about 35 feet high with massive trunks. I live in the Midwest where buckthorn is invasive and has been banned from being sold at nursery centers.

I knew it would be a labor intensive process to remove the buckthorn, but I didn’t anticipate how hard it would be to remove even the smaller shrubs. This will likely be a 5+ year project for me due to the amount of buckthorn and the process of removing the seeds/sprouts from my yard. I have a smaller suburban plot and I can’t imagine removing this from the space of a typical yard.

My husband thinks I am nuts for tearing down a perfectly good hedge and so do my neighbors. No one has said anything to me directly yet and my husband just lets me do my thing. I’m planting natives in the non-buckthorn areas of my yard to fix the damage and bring life into my yard.

Some days I look out into the backyard after hours of labor and the destruction process looks so bad. It takes so much work to do the demolition needed to build a life-giving garden. Anyone else feel like it’s futile sometimes? I won’t give up but I will never underestimate the damage invasive species can cause even in a small area again.

Since Reddit seems to have a large amount of interest in niche subjects, I've decided to start posting here.

My name is Tyler, my qualifications are: B.Sc. Plant Science, M.Sc. Agriculture (thesis was on knotweed control) and I’ve been managing the species on a case by case basis through my company: knotweed et al. Most cases have been successful (however, not all which I can elaborate on in comments - as time allows). I'm based in Nova Scotia, Canada. As a result, parts of this post are tailored to Canadian audiences.

Thesis Link: https://dalspace.library.dal.ca/handle/10222/81496

I don’t mean to be preachy, but I feel there is a need to address certain bits of misinformation I’ve seen pop up. These tips will save you some money, time, and reduce the spread of this plant around the province (I hope).

1. Stop Excavating the Stuff

This will not help with management of the species. It requires careful and thorough chemical control. The best case scenario for control is to have healthy and intact tissues to translocate herbicide down to the roots. Excavation simply exports the problem to another place in the province (which isn’t well equipped or aware of how much their existing practices are spreading the species around). And anywhere the heavy equipment goes, it could be contaminating more areas (especially if things are not cleaned between jobs). It takes something as small as 1 cm of stem or root (rhizome, underground stem) to propagate the species. And trust me, the excavator will miss some and create more propagules. Making it harder to control by turning treatments into a game of whack-a-mole. I’m considering refusing service to these cases until the knotweed becomes reestablished because it becomes too difficult to control after this.

2. Self-Directed Management

Absolutely possible. For limited patches, make sure you are using a glyphosate containing herbicide at the correct label rate (make sure it is only glyphosate). The most important element of treatment is ensuring that you treat the entirety of the canopy (or as much as you can treat). I’m not going to get into the nuances of dealing with the larger stands in this post (you can see some of those cases on facebook). It’s very very important that you treat as much of the contiguous area of Knotweed as possible within a growing season. This will significantly reduce surviving stem density in the following year. For smaller stands (populations), if you can treat the entire canopy from the perimeter, do not cut it down. Cutting stimulates lateral growth, meaning the Knotweed is likely to spread underground and create more problems. Treating only portions of contiguous populations won’t be particularly effective.

3. Chose Appropriate Equipment for Application

I use a telescopic spray wand (it’s about 1.5 meters long at maximum). Makes reaching into the taller canopy much easier. I’ve seen a lot of cute posts with people going at it with spray bottles of pre-mixed round up. Trust me, there is a better way.

4. Timing your Application

The vaunted “window” is based in scientific literature. Approximately 80% of the carbohydrates Knotweed fixes (via photosynthesis) are sequestered between August and September in their roots. Making it an ideal time to apply glyphosate. However, pretty much anytime after it stops growing vertically is acceptable for a pesticide application. This is end of June/ July. It can be risky to wait for too long, as you could have an early frost in your area and lose the opportunity to manage the species. My general rule of thumb for NS is after October 20th, you’re risking a 50% chance of treatment failure.

5. Don’t Tarp

Reasons: A. Dormancy is not death B. Microplastics (probably, I only have suspicions) C. Better long term control with herbicides, + native species in the seed bank won’t be coming back if you tarp.

I’ve got cases that are now in the two years plus of Knotweed being gone. It’s somewhat refreshing to see the native biodiversity coming back. If you tarp, and just bring in fill, that diversity might be lost.

6. Apologies for not getting to all requests for service this summer.

This summer has been my busiest year yet, I’ve taken on projects that are much larger scale and require public or stakeholder consultation (those cases will be published in coming months).

I’m a one man operation, and my systems were not set up for this much activity + I have another full-time job. I’m hoping to get around to all cases eventually. and appreciate peoples patience.

7. We Need Political Involvement (unfortunately).

As much as I don’t like bureaucracy, the province needs a unified strategy to deal with the species. There are many cases where I am unable to intervene due to the Knotweed being in places that don’t have private ownership (or stewardship). Along roadways comes to mind specifically. While I have some flexibility in the department of transportation not to interfere with management, it’s a drop in the bucket compared to the whole province. Right to your MLA about developing a unified strategy for the species. Obviously, pesticides will not be the most appropriate strategy for all locations, but the least we could do is reduce its spread and by ourselves some more time to come up with a plan. The big thing that comes to mind is vegetation management in ditches. The big bladed implements that run along the side of the road are amazing at spreading Knotweed during the summertime. Maybe… don’t do it?

Thank you for coming to my TedTalk.

Edit: TLDR

Don’t excavate knotweed, you’re exporting the problem, kill it where it is. Glyphosate only herbicide (domestic version is good). If you need more comprehensive advice, email me. However, it might be January before I answer due to case volume.

Obligatory, pesticide labels are law. Follow them to the letter. There’s no need to use concentrate directly on the Knotweed. You’re just going to cause treatments to fail.

Another note: It’s almost a different species in North America compared to its native range due to lack of significant predators. Still querying the status of the biological control Psyllid… ask CFIA maybe…

Has anyone started a business specifically focused on removing invasive plants and replanting native ones? What is the market like for this kind of work?

Where do dingos fall in terms of invasive species and possible control of other invasive animals in Australia considering they have been naturalized for a few thousand years

hey all, I live in the northeast and have some oriental bittersweet growing on my property. I know mid-late fall is the best time to apply herbicide since the plant is focusing on transporting as much glucose as possible--I've been waiting to apply as it has been raining for nearly a week straight, but now that it's sunny again we've also had our first couple of frosts.

I have Bonide stump-out stump & vine killer (triclopyr as triethylamine salt), and I was planning on making a cut near the base of the plant and painting the triclopyr on the fresh cut. Would this method still be effective after having a frost or two?

This little huntress just killed a spotted Lanternfly on my deck in Washington DC.

I live adjacent to a subdivision commons area, which is adjacent to a large (> 300 acres) city-owned park for hiking and mountain biking. Oriental bittersweet is taking over but most people are oblivious and/or unconcerned - "it's natural!" This means people aren't behind any type of eradication efforts.

A neighbor has rescued many huge trees by window cutting the roots and has trimmed back lower branches to keep trails open. But it's a losing battle for one person, or even a small group. So far the city has done nothing.

Two questions:

1. What's the end of the story? Once bittersweet takes over and kills the trees in its path, does it just keep growing in mounds over the fallen trees?

2. Any recommendations for helping people to understand the threat? Maybe pictures / articles about some of the worst areas?

Has anyone tried to burn a large honeysuckle stump? I've used a sawza to cut as far down as possible and my honeysuckle Popper tool is not able to pull out the root system. Considering placing rocks around the stump and burning it so that I have a flat ground area. Thoughts?

Went to a house viewing and saw this in the garden. Is it japanese knotweed?