QUESTION: We have clumps of spiderwort popping up all throughout the perennial beds. The little flowers are pretty, but the plants are taking over parts of the beds, and more I pull up the more they grow. How do you get rid of them?
It is hard to remain neutral about spiderwort (Tradescantia virginiana) if you’re a gardener. Either you love it for its pretty blue flowers and the fact that it grows without complaint just about anywhere, or you hate it because it’s a thug that muscles its way in and runs over everything else in the garden.
The individual blooms last only for a day, but the buds grow in large clusters, and some are always blooming. That’s one of the good things about spiderwort. It reproduces by letting its seeds blow all over the place, which is why you’ll find spiderwort suddenly growing up in inconvenient places – through the center of a clump of favorite daylilies or in the middle of the iris bed, as they do in my garden, for example. Not so good.
Getting rid of it is not easy. The roots are strong and fleshy and grow in large, wide clumps so pulling it out only works when the plants are very young. Digging is required, and you must dig up every bit of it because what’s left in the ground will grow into more spiderwort. If you feel you must bring in the chemicals, use a product that contains glysophate (such as Roundup), but use it only as the label advises, and keep it from drifting onto other plants.
It may be easier to control spiderwort if you deadhead it (cut off the flowers before they can disperse seeds), and pull up new shoots as soon as you see them emerge from the ground.
I remember visiting a friend’s shade garden several years ago and seeing a vigorous clump of spiderwort growing at the edge of the path. She was surprised when I told her that I dig it up and toss it out whenever I find it in my beds. “The little flowers are pretty,” she said. “And it grows so well in the shade!”
Yes, that’s the part to love. Just remember how watchful you have to be to keep it from taking over your yard.