Galega officinalis aka Goat's Rue

Galega officinalis is a perennial in the pea family, Fabaceae. Its common names include goat's rue and French lilac. Kew places its native range from central and southeastern Europe to western Pakistan. It grows in temperate regions. Recorded habitats include scrub, woods, wet fields and roadsides. It forms a bushy clump and loses its leaves each year.

Garden plants reach 3.3–4.9 feet [1–1.5 metres] tall. Their spread reaches 1.6–3.3 feet [0.5–1 metre]. They take about two to five years to reach full size. The stems carry pinnate leaves, split into separate leaflets. Pea-like flowers grow in upright racemes above the foliage. Their colours range from white through lilac to purple. Bloom runs from midsummer into early autumn.

An open site in full sun suits this plant best. It also accepts light shade. It grows in chalk, clay, loam or sandy soil. Acid, neutral and alkaline soils all suit it. Give it moist soil that drains well. RHS rates it H7 for cold hardiness. PFAF lists USDA zones 4–8. Rich soil can lead to fast spread, and stems need staking. Cut off spent flowering stems to limit self-seeding. Sow seed in spring after soaking it overnight in warm water. Divide clumps in spring or late autumn.

Goat's rue suits cottage gardens, informal beds and flower borders. PFAF also lists meadows and sunny woodland edges as settings. Its fast growth makes it useful as a green manure. It fixes nitrogen and adds organic matter to soil. These traits come with a risk of unwanted spread. Aphids and pea and bean weevils may damage plants. Powdery mildew can also affect them.

PFAF records cooked leaves as food, but also warns of possible toxicity. Reports describe poisoning in mammals, so food use carries a clear caution. The herb has also served to curdle plant milks. Other recorded uses include cosmetic hand and foot baths. Herbal traditions use the leaves and flowering tops for several purposes. These include promoting milk flow, increasing urine output and treating fevers. The plant contains galegine, which can sharply lower blood sugar. These records describe uses, not proof that home treatment is safe.