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Goutweed is a fast-growing groundcover for dry, shady spots where nothing else will grow. In better conditions, it can quickly overtake less vigorous plants.
Other Common Names
Snow-on-the-mountain, bishop's weed, ash-weed, ground ash.
Goutweed leaves are deeply divided. They may be all green or green with irregular white edges. The flower heads are white or yellow, umbrella-shaped clusters that bloom in June. Goutweed grows in patches.
Goutweed grows 12-14 inches (30-35 cm) tall; the flowers are about the same height.
Preferred Site and Climate
Goutweed tolerates shade and infertile soil; it will spread more rapidly in moist conditions. It is most commonly found in the eastern United States.
How it Spreads
By seed and rhizomes (creeping underground stems).
Digging out the rhizomes can reduce the size of a clump, but it's almost inevitable that you'll miss a few rhizomes. Pull, hoe, mow, or cut shoots or existing plants to the ground every 1-2 weeks, until plants stop resprouting. Or cut them back, then cover the area with a dense mulch, such as newspaper, cardboard, or plastic. The keep goutweed controlled as a groundcover, sink barriers at and below soil level.
If you dig plants, don't toss the fresh roots into the compost pile; spread htem out in the sun until they're thoroughly dry to kill them first.