I'm interested in which invasive plants are a problem for you all and what your successful tactics to deal with them are.
I have many plants on my farm that people are afraid of. I am not afraid of most of them.
Some I leave alone completely unless they are being used or are right in the way(dandelions, dock, etc.) Some I leave a few plants of, removing most of them (poke) and some I get rid of all that I can, with confidence that there are plenty of them in other places and I'm not likely to get rid of them all (bindweed, Asian bittersweet, Asian honeysuckle)
The ones that really bother me are rhizomatic vines. They grow up and around other plants and trees, blocking their sun and airflow. Leaving any piece of the root means the vine will come back. Breaking roots and pulling tops can mean faster more vigorous growth.
I do my best to pull all the vines and get the root when possible. It's really a problem for a perennial forest garden.
With the bindweed, the most success I've had is with twirling it into a bundle without breaking it and covering the bundle with a heavy rock and then a 5 gallon bucket. Then, coming back on a regular basis to tuck any new growth under the rock and bucket. This works but it's a lot of work and I don't have enough rocks or buckets, never mind enough time! I just can't keep up.
The other vines are easier to manage because their stems are still tough in the winter so I spend the time where plants are not really growing but the ground ifs not frozen pulling all the vines down and digging up the roots. Bittersweet is mostly beaten back now to the places where the roots are entwined with my trees' or under stone walls.
Still, I am only one person on my farm most of the time these days doing the bulk of the work while taking care of three kids three and under. I spend a lot of time on these plants, so advice and tactics are very welcome.
Does anyone have a forest garden in a place where invasives grow. Is it possible to someday have a low work system?
I hear you about bindweed. I am lucky to "only" have it in one large infested area of a few hundred square feet. I'm in the process now of covering this area with about two inches of well composted horse manure, then a layer of wood chips, grass that was cut by scythe, more manure and finally more chips. The soil is in an old barnyard but I'm not keeping horses or other large grazers so the area now is truly a waste area. It is badly compacted by past use/misuse. I assume the bindweed won't mind all of the added OM so I plan to cover the entire area with black plastic left over from a construction project last year. I will keep that area covered probably all next growing season. When the cover comes off, finally, the resulting amended soil should be much more conducive to planting more "desirable" species like food plants and supporting ornamentals. I have been surprised to find bindweed in a few spots in some hugelbeets that I thought were free of the plant last year. Those I'm checking every few days and pulling them up. Don't know how it spread to these new spots but it seems to be effective to keep pulling them until they are exhausted. They may be deep rooted but they've got to photosynthesize like all plants. They can't use their root reserves forever. This one species is likely the most pernicious of all that I'm dealing with.
My other big contender is white top (Cardaria sp.). It is perennial, rhizomatous, and so widespread on my place, I will likely never be rid of it entirely. I will say this for white top, it covers disturbed soil with a fairly low decent cover. The bees went crazy over the flowers last year (it's in the mustard family) but didn't seem as busy on them this year. I've kept it mowed/scythed in larger areas and pulled by hand and left to rot on my hugelbeds and raised annual garden beds. It's growing under my pumpkin "forest" at the moment even though I kept pulling it until the pumpkins got going and totally took over the area. My guess is, based on my observations of my more successful hugelbeets, is that Cardaria isn't the most competitive plant out there in areas where other large, fibrous rooted perennials are growing. My abatement tactic will be to continue pulling and using it for mulch and plant heavily so that the rooting zone is filled with other, more desirable species.
For Scotch thistle, I just pull them as I find them. I have far fewer than two years ago. It's biennial and if you see the first year rosette, just pull it up and it's game over.
I've pulled all the spotted knapweed I've encountered. I pulled many dozen last year in one specific area and only pulled three this year so I just have to be watchful for another five to seven years. Based on what I've read, the seed is viable for about seven years in the soil. Unfortunately, it is ignored in many semi-urban areas around, and covers huge areas of wildlands here so it's not going away anytime soon. They are easy to spot this time of year because of their lovely pink flowers. Bees love them, but they are alleopathic and have degraded many tens of thousands of acres of Montana.
Canada thistle is my only other PITA weed. I pull it and mulch with it whenever I am working in an area. It doesn't seem as abundant as two years ago when I moved here. I found a few in the last few days that escaped my watch and have set seed. Those will be cut off and bagged and disposed of with the household garbage.
I have the same problem. I have wild blackberry spreading like crazy, winter creeper, honeysuckle vine, wild grape vine and a forest of pokeweed. Oh, and pigweed came from somewhere last year. . . .It has taken most of my available garden time just to prevent these things from seeding and completely taking over.
With the pokeweed I have found their roots are impossible to dig up and they will come up thru sheet mulching. I'm going to try heavier sheet mulching in an area and see if I can exhaust the root systems. I've done some research and apparently the seeds can remain dormant in the ground for years and years. I made the mistake of having a 50'dia area bush-hogged and didn't get it covered quickly enough. Lesson learned.
Same thing with the blackberries. Actually, all of these "invasives" are primarily in the same bush-hogged area. I'm leaving the wintercreeper which is creating a dense carpet over the ground to help prevent other or additional invasives from coming in. I will work inward with heavy sheet-mulching, in small areas to try and correct this.
I'd like to learn of any better techniques for dealing with this.
Location: Southern New England, seaside, avg yearly rainfall 41.91 in, zone 6b
Poke is an easy and fun one. I've dug up massive roots in the past. Lots work, and you can never get every bit.
My new tactic is to step on it almost daily. Crunch! It keeps sending up shoots but it can't make it to maturity. This is my first year of trying this method but I'm satisfied so far. The nice thing for me especially right now is that I'm usually carrying around a baby and this is a hands-free job.
Mice tend to stockpile poke seeds around here. I think maybe they don't like to eat them but save them just in case of winter hunger.
One way or another, poke is pretty easy, you can also take a knife/sickle with you walking around and chop and drop. I'm impressed at how quickly poke can grow so large. It looks sort of gross when it dries out, like soaked toilet paper.
If you got it down once a week I bet that would weaken the vigor of the roots a lot.
Isn't it amazing how quickly the pioneers come in after a disturbance?!
Cutting it down is easy, the problem is how much of it I have. Truly about 2,000 SOLID sf. I can't possibly cut that down every week with the rest of the yard, garden, animals and a full-time job. And I really can't dig out all of those roots - at least not by hand. I'm desperately seeking a way to eliminate the most of this. I'm sure there will always be some coming up somewhere, but the dense forest of it has to stop. I can post some photos later tonight to show how bad it is.
I don't know much about Bindweed, except that I'm pretty sure cows will eat it. I know Bittersweet is mostly a hands on problem. And the NRCS Organic method for Honeysuckle is cutting and spraying of high percentage vinegar. Both can also be managed with mob stocking of goats. As for other weeds that are problematic but not necessarily invasive, like Blackberry, it could be a matter of ph. Soil testing will likely reveal an acidic soil where there are thickets of Blackberries. Liming can make a big difference. Balancing ph helps to release nutrients that are present but cant be used by desired species(grasses).
I've made some progress with some of these invasives, but bindweed is really something else. We've got three tiny infestations, but since I recognised it I've been pulling all I can find every week or two all summer for three years. It hasn't had a chance to flower or even set a bud, and I think I started when there was only one small area, so I don't think the new outshoots are from seeds. It's incredible -- after you pull some, you'll find it shooting up 6 feet away a week later. So I like the suggestion of bundling it under a cover -- maybe pulling it is making it shoot up in a new area. It doesn't seem to get much weaker from what I've been doing.
Works at a residential alternative high school in the Himalayas SECMOL.org . "Back home" is Cape Cod, E Coast USA.
Diego Footer on Permaculture Based Homesteads - from the Eat Your Dirt Summit