Common Meadow Weeds

Knowing whether a weed is an annual, a biennial or a perennial tells you how to control it. These are the species that most often compete with new meadow seedings in the Mid-Atlantic, grouped by how they grow.

Annual weeds

Annuals live for a single season and come back from seed, so controlling them is a matter of stopping them from setting seed. The first-year mowing schedule takes care of most of them.

• Crabgrass and foxtails are warm-season annual grasses that flush in late spring on disturbed soil.
• Common lambsquarters and pigweeds are fast-growing broadleaves of rich, disturbed ground.
• Common ragweed is native, but it’s a heavy competitor in first-year seedings, so mow it before it flowers.
• Japanese stiltgrass is an invasive annual grass of shady and moist edges. Mow or cut it in late summer, before it sets seed.
• Mile-a-minute is an invasive annual vine with triangular leaves and barbed stems. Pull or cut it before its blue berries ripen.

Biennial weeds

Biennials form a low rosette in their first year and flower in their second. Cut or dig out the rosettes, or cut the flower stalks before seed forms.

• Wild carrot (Queen Anne’s lace)
• Bull thistle
• Garlic mustard, which invades shade and woodland edges and should be pulled before it flowers in spring

Perennial weeds

Perennials come back from their roots or rhizomes, so mowing alone won’t get rid of them. Spot-treat them with herbicide, timed for when the plant is moving energy down into its roots, which is usually at bud stage or in fall.

• Canada thistle spreads by its roots to form patches. Treat it at bud stage and again on its fall regrowth.
• Mugwort is rhizomatous and persistent, so expect to treat it repeatedly over several seasons.
• Tall fescue and other cool-season turf grasses hang on from old lawns and pastures. Spot-treat them in early spring or late fall, when they’re green and the warm-season natives are dormant.
• Common reed (non-native Phragmites) invades wet sites. Treat it from late summer into early fall, and bear in mind that work in wetlands may need permits.
• Japanese knotweed is extremely persistent. Treat it from late summer into fall, and plan on several years of follow-up.

Woody invasives

Mow woody seedlings while they’re small, and cut and treat the stumps of larger plants. Multiflora rose, autumn olive and Oriental bittersweet are the most common. Tree-of-heaven is the exception to the cut-and-treat approach: treat its standing stems instead, because cutting it first triggers a flush of root suckers.