Pulling the Devil's Hair

What's that--a piece of yellow string? 

Have you found any devil’s hair in your garden?

The devil has been primping in our garden. I know because I’ve found devil’s hair. Devil’s hair has other common names that indicate the fear it engenders wherever plants are grown, including devilgut, devil’s ringlet, hell bind, stranglevine, and strangleweed.

This plant isn’t a positive addition to any garden, except, perhaps, one where sulfur fumes waft from brimstone pits and temperatures are significantly higher than those of Mid-Atlantic Summer 2011. Devil’s hair is dodder (Cuscuta spp.), of which 10 of the world’s 150 varieties grow in Maryland, according to USDA maps online.

A tangle of devil's hair

“Grow” somehow doesn’t seem like the best verb to use with this parasitic plant—which has leaves that usually are more like scales, often nearly invisible. It has little or no chlorophyll so must attach itself to a host plant to suck nourishment within a few days of sprouting—or it dies.

“How did that yellow string get into our bed of moss phlox?” I thought when I first saw the parasite. I looked closer and found the string was tightly twined around phlox stems and was blooming, with small white flowers.

This string is not welcome in farm and garden country because its hosts include such food crops as asparagus, beet, carrot, eggplant, garlic, melon, onion, pepper, potato, sweet potato, tomato, plus a wide variety of other plants ranging from chrysanthemums and azaleas to alfalfa, clover, and legumes.

Moss phlox strangled by blooming dodder

Dodder can be a real hell bind in large agricultural settings, but in a relatively small home garden its control usually is relatively simple: hand pulling the devil’s hair before it goes to seed, pruning parts of hosts that it’s strangling, and treating this year’s dodder areas next spring with a pre-emergent herbicide to eliminate a new crop.

I’ve pulled every piece of the blond devil’s hair that I can find, but I suspect I haven’t got it all in the tangled mass of moss phlox. I’ve sprinkled some Preen, a pre-emergent herbicide, in the general area to prevent any remaining seeds from sprouting this year, and I’ll put down more Preen next spring.

I’ve been checking the moss phlox every few days and discovered that the dodder comes back quickly. I’ve learned that “pulling” the dodder doesn’t solve the problem if I leave remnants with roots embedded in the stems of the host plant. I’ve gone back twice with my pruners to cut off regrowth of the dodder an inch or so below where it has a stranglehold on the phlox.

This is the kind of problem that will take vigilance to solve, so whenever I walk by the moss phlox, I’ll pause to inspect to make sure there are no new strands or tangles of devil’s hair.

If you have a minute to look at some fantastic dodder photos, CLICK HERE to access the website of the dodder page of the Biology Department of Swarthmore College.