I'm reposting this from the "pests and diseases" forum, at ecrane3's suggestion. I don't think chickweed is technically an "invasive plant," but there seems no place else to ask weed questions.
Has anyone been successful in eradicating a bad dose of chickweed? Year after year my perennial garden gets covered in the stuff. I weed it faithfully before it blooms, but if I go away for a week or two when I come back there's a carpet. I'd be interested to know, also, if others have had my same experience. At least then I'd get a sense that there's no magic solution.
Was just doing a bit of reading - on paper chickweed sounds diabolical: probably the most common weed in the world, several generations a year, up to 15,000 seeds per plant and seeds that can last up to 25-40 years.
Nevertheless, my own experience with a number of patches of chickweed in flowerbeds agrees with sources that say a couple of years of hand pulling or hoeing will reduce the problem to easy management. Chickweed is a small, brittle annual. You don't need to get rid of the roots and severed plants, just stop the plants from maturing and producing seed. For seeds that germinate, hoeing is an efficient way to eliminate the seedlings.
I've got Chickweed starting to suffocate my beautiful Periwinkle all around my deck. When I pull it out I get runners two to three feet long that usually drags some Periwinkle with it ... and the weed just keeps coming on.
It got me mad enough to search DG for an answer.
I'm assuming that my ordinary turf friendly weed killer ( Weed-B-Gon ) would be a bad idea here, right?
That's not chickweed, it's some sort of bindweed or something else in the morning glory family. If you've got a paintbrush handy you might try carefully applying your weedkiller just to its leaves and avoid your periwinkle. The trouble is anything that kills the bindweed is also going to kill the periwinkle so you'll have to be very careful in the application.
I think it's bindweed. In my experience, if you don't keep an upper hand on that stuff it grows well, like a weed, and it produces a lot of seeds and each one of them grows!
If it were me, I'd spray the whole lot, periwinkle and all, IF you have a really bad case of bind weed. It would be easier to re-place the periwinkle than try to keep fighting the bindweed. It will be wrapped around your periwinkle and you would probably miss some only for it to re-seed. That stuff is tenacious.
I did have good luck with some bindweed around my iris and peonies. I carefully sprayed the bindweed with round up and then put a plastic grocery bag on it and loosely tied it shut. It died. But that was for one plant. It was winding around my peonies. You have to catch it before it goes to seed.
If you have been having as much trouble as it sounds, I'd blast it with round up. I would leave the garden empty for a year and continue to spray it with round up next year. It is hard to get rid of once it goes to seed. I know spraying the periwinkle and the bindweed is quite aggressive, but I don't think you'll get rid of it any other way.
That's just my opinion and what I would do. Good luck!
As for bindweed that has wrapped around stuff... I follow the stem to the ground and then pull it out, leaving the wrapped bindweed which, of course, dies, having been pulled from the ground. Sometimes an infestation that looks huge is only a few plants if you find the growth point.