Black Swallow Wort is as hard to get rid of as black flies in spring.
You want to make sure none of its seed pods burst open and shower creation with zillions of possible black swallow wort babies. Those pods ripen and burst open around mid to late August here.
Some use a chemical spray, but using even home remedy sprays – vinegar and dish soap, for example – invariably affects plants around your target weed.
Pulling it up by its roots in nearly impossible; it grows from a rhizome and unless you are able to dig the entire rhizome out, the weed will just sprout again in the spring. Besides, since it usually grows near and around other plants, you will run into those roots digging around after that rhizome and probably damage them as well.
Cutting the vines and pods may be one of the best ways to ensure none of its seeds survive.
Each August, a hearty crew of volunteer pod pickers attacks the Swallow Wort vines and pods that have invaded Ogunquit’s Marginal Way. Every year some 800 pounds of vines and pods are cut out and bagged over a several hour period – an unbelievable amount given these vines are so thin and the pods just a few inches and nearly weightless.
In our garden we cut down the Swallow Wort sprouts and vines every week or so in growing season so it cannot grow its seed pods, hoping we are stunting the plants.
Some cut the plant off near the ground and then brush the stem that’s left with a gel version of Round Up, but usually this is done by a licensed applicator.
Now is the time for you to check your garden and along your property and cut out this nasty menace before its seeds shower your garden and nearby areas and create even more Swallow Wort next year.
A WARNING: YOU CANNOT COMPOST THE SEED PODS. TAKE OR SEND THEM TO THE TRANSFER STATION TO BE BURNED. THAT’S THE ONLY WAY TO MAKE SURE THE SEEDS WON’T GROW MORE SWALLOW WORT.