365 Urban Species. #160: Black Swallow-wort

[urbpan]

Location: Price Road, Allston.

Urban species #160: Black swallow-wort Cynanchum nigrum

Tiny star-shaped flowers , so dark purply-brown they look black, are the primary charm of this weed. Later in the season it develops pods that release seeds that float on silken parachutes (similar to, but more restrained than, cottonwood). It twines up chain-link, putting glossy dark green green foliage on ugly fences. Its attractiveness cause it to be introduced to North America as an ornamental. Unfortunately, there is little else that is positive about this plant, at least as it exists outside of its native range of Eastern Europe.

It is strongly invasive, and has several deleterious effects. Like other members of the milkweed family, it is poisonous. So when it crawls in among crops or pasture fields, it makes mechanical harvesting impossible, and whole pastures unusable by livestock. When it invades grasslands, there is a population drop among birds that nest in such areas. Monarch butterflies recognize it as a milkweed, and lay their eggs on it, but their larva are unable to feed on it, and starve. It joins garlic mustard and Japanese knotweed on the "least wanted" list, for New England native plants enthusiasts.

Comments

[larksdream]

The hatred! The hatred!

Swallowwort is the bane of my gardening existence. It will not die. If you pull it but don't dig out the whole root, it resprouts from broken-off pieces left in the ground. Roundup, a relatively benign herbicide, doesn't even faze it. Investigating online revealed that it is susceptible to the active ingredient in Ortho Brush-B-Gon. I hate using sprays-- except for my battle with swallowwort I have an organic garden-- but it was that or have the entire garden eaten by swallowwort. So I spot-sprayed the worst stands, including places like along the fenceline where it's impossible to pull up all of it. Die, swallowwort, die. I hate you.

black swallow-wort

[blackthorne007.livejournal.com]

I HATE THIS STUFF !! You're absolutely right about what a pain-in-the-posterior this weed is deal with. I just found this post while trying to figure out what this and some other noxious weeds were. Have you noticed it's really stinky when you pull it ? The stench is enough to make me gag after a while. I apologize if that was too much info. I'm afraid this stuff just makes me nuts. ;)

black swallowwort

[(Anonymous)]

I have this stuff invading my garden as well and share your frustration. How did the Ortho Brush-B-Gone work? I'll try anything to get rid of this stuff!!! Please help!!

Re: black swallowwort

[larksdream]

Yes, it does kill it. Although it can be hard not to spray nearby plants as well, depending on where it's growing-- I've heard some people use a glove or a brush to apply the Brush-B-Gone to the target plant.