Geranium erianthum aka Woolly Crane's Bill

Geranium erianthum is a deciduous perennial in the Geraniaceae family. Its common names include woolly cranesbill and woolly geranium. Its native range spans southeast Siberia to northern and north-central Japan. It also extends from the Aleutian Islands to western Canada. It grows in woods, meadows, scrub, and grassy coastal slopes. These sites range from low ground to mountain meadows.

The plant forms clumps rather than a woody frame. Garden plants stand about 1.5–2 feet [0.45–0.6 metres] tall. The RHS also lists an upper height of 3.3 feet [1 metre]. Spread can reach 1.6 feet [0.5 metres]. The pale green leaves have seven to nine lobes. They measure about 2–8 inches [0.05–0.2 metres] across. Their autumn colour adds interest before the foliage dies back. Plants reach their full size in two to five years.

The flowers form shallow cups with clear, darker veins. Their colour ranges from light to deep violet-blue. Each bloom measures about 1–1.6 inches [0.025–0.04 metres] across. Flowers open from late spring through the middle of summer. A further flush may follow in summer or early autumn. The plant suits beds, borders, and informal cottage gardens. It also fits courtyard gardens and planting beneath roses or shrubs. Woodland edges and sites with dappled shade offer other settings.

Grow it in full sun or partial shade. Keep the soil moist, but allow excess water to drain. It accepts chalk, clay, loam, and sandy soils. Acid, neutral, and alkaline soils all suit it. The RHS gives it the cold-hardiness rating H7. Plants For A Future lists USDA zones 3–7. No routine pruning is needed. Removing spent stems and old leaves may prompt fresh growth and flowers. Sow seed outdoors when ripe or in spring. Clumps can also be divided in spring.

Pests and disease cause few problems in most cases. Slugs, snails, capsid bugs, sawflies, and vine weevils may attack it. Possible diseases include rust, downy mildew, leafy gall, and viruses. Dry conditions may bring powdery mildew. Plants For A Future records edible leaves and flowers. Leaves can be eaten raw or cooked, though their food value is low. Flowers can be eaten raw. That source lists no known hazards, but gives no pet-specific safety assessment. It also records medicinal use of the plant, chiefly its roots, as an astringent and styptic.