Stellaria media aka Chickweed

Stellaria media, or common chickweed, belongs to the carnation family, Caryophyllaceae. Its native range covers temperate Eurasia and parts of Africa. These include northern Africa and northeastern tropical Africa. It is native to Britain and Ireland too. It now grows throughout the United States. This cool-season herb lives as an annual, sometimes a biennial. It can keep some green leaves through winter. Mild weather lets it grow all year.

Plants sprawl and branch most near the base. Garden height ranges from about 0.3–1.6 feet [0.1–0.5 metres]. Spread reaches about 1.6 feet [0.5 metres], according to RHS. NC State gives a narrower spread, reaching 1 foot [0.3 metres]. The soft stems may be green or burgundy. Lines of white hairs run along them. Small, bright green leaves grow in opposite pairs. They have oval outlines and smooth edges. Lower leaves have short stalks; upper leaves lack them. The leaves fold around young shoot buds at night.

Small white flowers appear from spring through autumn. Each plant may flower off and on for one to two months. Each bloom has five deeply split petals, which look like ten. Flowers grow from leaf axils and in small terminal cymes. They open in the morning but stay shut in dull weather. Brown seed capsules follow, with six teeth around the rim. Each holds several tiny, reddish-brown seeds. Plants can bear flowers and seeds at once.

Grow chickweed in sun or partial shade, with moist, well-drained soil. It accepts clay, loam, sand, and chalk across the pH range. Rich soil fuels lush growth; poor soil prompts early seed production. RHS rates it H7, while NC State lists USDA zones 4–11. It grows fast, with strongest growth in late winter and early spring. It needs no pruning and has few pest or disease problems. Yet it can become a persistent garden weed. NC State reports an invasive listing in North Carolina. Stems root at nodes, and seeds can survive 25 years underground. Shallow roots make unwanted plants easy to pull.

Chickweed supports bees, butterflies, songbirds, and moth caterpillars. Chickens also eat it, which explains its common name. People eat its leaves, stems, flowers, and seeds. Young leaves serve as salad greens or cooked greens. Ground seeds can thicken soup or go into bread. The plant also has a history of external herbal use for itching. Its leaves contain saponins, so avoid eating large amounts. Thorough cooking breaks down these compounds. PFAF warns against use during pregnancy or breastfeeding. Excess intake can cause vomiting and diarrhoea.