Aegopodium podagraria aka Ground Elder

Aegopodium podagraria is known as ground elder or goutweed. This herbaceous perennial belongs to the carrot family, Apiaceae. Its native range spans temperate Europe and Asia. It has also spread into much of the United States. It grows in hedges, fields, pastures, and disturbed woodland. Several US states class it as invasive in natural areas.

Ground elder forms dense patches and loses its leaves seasonally. Garden plants reach about 1–2 feet [0.3–0.6 metres] tall. Flower stems can reach 3 feet [0.9 metres]. Reported spreads range from 1–5 feet [0.3–1.5 metres]. Underground rhizomes let patches extend beyond these bounds. Its green leaves have a compound shape with three leaflets. Their edges have teeth, and the leaves smell of carrots. Fleshy leaf stalks join the underground stems. Shallow roots form a dense network beneath the foliage.

Small white flowers rise above the leaves on leafy stems. They form flat umbels about 0.25 feet [0.08 metres] across. North Carolina State lists flowering from May to June. The RHS reports a wider season, from spring into autumn. Bees, beetles, and flies visit the flowers. Small, long, brown seeds ripen in late summer. Both seeds and rhizomes help the plant spread.

Ground elder grows best with some shade and well-drained soil. It accepts clay, loam, sand, and a wide pH range. It tolerates dry soil, deep shade, compaction, and deer. Strong summer sun can scorch its leaves. Summer heat may also cause the foliage to decline. Sources give USDA zones 3–10 and UK hardiness H7. It can cover banks or less tended wildlife areas. Yet its spread makes it unsuitable for many planted borders. Dense patches crowd out native plants and hinder young trees. Even small root pieces can regrow, making removal difficult.

The RHS reports few pest or disease problems. North Carolina State notes leaf blight in hot, humid weather. Containing its spread can demand much work. Leaves are edible raw or cooked, with a tangy taste. Gather them before flowering for the best flavour. They can go into soups, salads, or cooked vegetable dishes. People once grew this plant for food and medicinal use. Traditional uses included gout and arthritis, but these are not proven treatments. Plants For A Future lists no known hazards.