How to Grow Hardy Geranium (Cranesbill)
Perennial
Hardy geraniums, also called cranesbills, are true perennial geraniums with long flowering, spreading growth and beautifully divided leaves. They are not the bedding "geranium", which is actually a tender Pelargonium. Cranesbills are adaptable, easy-going plants that knit borders together and offer flowers in blue, pink, purple, white and magenta.
Planting
Plant hardy geraniums in spring or early autumn, choosing soil that suits the cultivar: most enjoy sun or partial shade and ordinary, well-drained garden soil. Improve poor ground with garden compost, then space compact varieties 30 cm apart and spreading forms up to 60 cm apart. Water well until established. Spring planting is especially useful in colder northern gardens and Scotland, while early autumn planting is excellent in milder areas.
Care
Water new plants in dry weather, but established cranesbills are generally undemanding. Apply a light spring mulch and trim sprawling stems if they wander beyond their allotted space. After the first main flush of flowers, shear back tired foliage and spent stems to encourage fresh leaves and, for many varieties, a second display. Divide vigorous clumps in spring or autumn when needed.
Bloom time
Depending on variety, hardy geraniums flower from May to September. Early forms bloom in late spring, while long-flowering cultivars can continue through summer and into early autumn. In cooler northern gardens, the season usually begins a little later. The flowers are simple and open, often with attractive veining.
Garden uses
Cranesbills are ideal ground cover beneath roses and shrubs, at border edges, on banks and in naturalistic planting. Their foliage fills gaps and suppresses some weeds once established. Low, spreading varieties soften paths, while taller forms mix well with cottage-garden perennials. Their open flowers provide useful forage for bees and hoverflies.
Tips
Choose the cultivar for its habit, not just its flower colour: some spread widely, while others form neat mounds. Cutting plants back after their first flush is transformative and quickly reveals clean new foliage. Do not confuse them with tender Pelargoniums used for summer bedding. AGM cultivars are a dependable starting point.
Growing Hardy Geranium (Cranesbill): frequently asked questions
How do I grow hardy geranium (cranesbill) in the UK?
Plant hardy geraniums in spring or early autumn, choosing soil that suits the cultivar: most enjoy sun or partial shade and ordinary, well-drained garden soil.
When does hardy geranium (cranesbill) flower?
Depending on variety, hardy geraniums flower from May to September.
How do I care for hardy geranium (cranesbill)?
Water new plants in dry weather, but established cranesbills are generally undemanding.
General guidance for UK gardens. Timing and hardiness vary by region and season; the RHS or a local garden centre can advise for your area. Page updated 18 Sep 2026.