Geranium nodosum aka Knotted Crane's Bill

Geranium nodosum belongs to the Geraniaceae family. It is a herbaceous perennial: a soft-stemmed plant that lives for years. Its native range runs from northeastern Spain to Croatia. It grows in temperate regions, where the climate is mild. It is not native to Britain or Ireland. Its common names are knotted cranesbill and broad-leaved cranesbill. It forms a bushy plant with a loose, sprawling shape. It sheds its leaves rather than keeping them through winter.

Plants reach about 0.3–1.6 feet [0.1–0.5 metres] tall and wide. They take two to five years to reach full size. The glossy leaves each have three lobes. Loose groups of flowers rise among the leaves. Blooms last from late spring into early autumn. The light pink petals have darker veins across them. Each bloom measures about one inch across. This small plant blooms for a long season. That makes it useful in mixed beds. Its spreading shape also suits use as ground cover.

Grow it in full sun, part shade, or full shade. It accepts chalk, clay, loam, and sand. Acid, neutral, and alkaline soils all suit it. Choose soil that drains well and is not too rich. It likes moist soil, but roots must not sit in waterlogged ground. It grows in both exposed and sheltered sites. The RHS gives it a UK hardiness rating of H5. Chicago Botanic Garden lists USDA zones 4–7. These ratings use different regional scales to show hardiness.

Use it in flower borders, cottage gardens, or informal planting. The RHS also lists gardens near the coast as suitable. It lists gardens grown for wildlife, too. Its low growth suits banks, slopes, and beds. It gives gardeners a choice where shade limits which plants bloom. Watch for seedlings from seeds the plant sheds. Without control, this self-seeding can make it a nuisance. Cut off spent flower stems and old leaves. This helps spur fresh growth and more flowers.

Grow new plants from seed, or split well-grown clumps in spring. Take basal cuttings from the plant's base in early to mid-spring. Heat from below helps these cuttings form roots. Watch for vine weevil and geranium sawfly. Slugs and snails may cause problems, too. Powdery mildew, downy mildew, and a virus may also affect plants. These problems may occur, but not every plant will suffer them.