Galium odoratum aka Sweet Woodruff

Galium odoratum, or sweet woodruff, belongs to the coffee family, Rubiaceae. This perennial grows wild across temperate Eurasia and Algeria. It is native to Britain and Ireland too. It grows in woods and other damp, shaded places. It often occurs in beech woods on lime-rich soil. Gardeners grow it for its flowers and scented leaves. Creeping rhizomes and seeds help it form low mats.

Most garden plants stand 0.5–1 foot [0.15–0.3 metres] tall. The RHS gives an upper height of 1.6 feet [0.5 metres]. Sources list spreads from 1.5–2 feet [0.46–0.61 metres]. The RHS allows for wider mats reaching 4.9 feet [1.5 metres]. Thin green stems have a square cross-section. They lie along the ground or lean over nearby plants. Narrow, smooth leaves grow in rings around each stem. Each ring holds about six to nine leaves. Crushed leaves give off a scent like cut hay. Drying makes their scent stronger.

Small white flowers form loose clusters above the leaves. Each star-shaped bloom has four petals and a sweet scent. Missouri Botanical Garden lists flowering from April to May. Chicago Botanic Garden gives a longer March to June season. Small fruits follow in summer. Each fruit is a schizocarp with hooked bristles. These hooks catch on clothes and animal fur.

Grow sweet woodruff in moist soil that drains well. Partial or deep shade suits it better than strong sun. It grows in clay, loam, sand, and chalk. It accepts acid, neutral, and alkaline soil. Strong sun can scorch the leaves. Summer drought may cause the plant to go dormant. Water during dry spells to help prevent this. Sources place it in USDA zones 4–8, with Chicago also listing zone 3. The RHS rates its cold hardiness H7. It tolerates deep shade and sites near black walnut trees.

Use it beneath shrubs, along shaded borders, or as ground cover. It also suits herb gardens and naturalized planting. Its spread can become a nuisance in good conditions. Routine pruning is not needed, and serious pests or diseases are uncommon. Dried leaves scent sachets, potpourri, and perfumes. Leaves flavor tea, fruit drinks, and wine-based drinks. Flowers are edible too, but large amounts may thin the blood. Herbal medicine has used the plant for several ailments. These reported uses do not establish its safety or effectiveness.