Hardy Geraniums — Growing Guide

Hardy geraniums, or cranesbills, are some of the most versatile and trouble-free perennials you can grow. Unlike the tender pelargoniums often sold as "geraniums", true hardy geraniums survive frost and cold winters, spread to fill gaps, and require minimal ongoing care once established. They are a staple of low-maintenance borders, cottage gardens, and shady areas where little else performs as reliably.

Popular varieties to grow

The range of hardy geraniums available is remarkable. Geranium 'Rozanne' is probably the most popular — it flowers for an exceptionally long season from early summer right through autumn with violet-blue blooms. Geranium pratense and its cultivars produce classic cranesbill flowers in early summer and self-seed freely. G. macrorrhizum is an excellent ground-cover plant for dry shade, with aromatic foliage and reliable pink flowers. G. psilostemon has striking magenta flowers with black centres and excellent autumn colour.

Where and how to plant

Hardy geraniums tolerate a wide range of conditions, from full sun to full shade, though most flower most freely in partial shade to sun. Plant in any reasonably fertile, well-drained soil. In very heavy clay, incorporate some grit to improve drainage. Plant at the same depth as in the pot, firm in well, and water after planting. Most varieties establish quickly and will spread to fill their allotted space within two to three seasons.

• Tolerates full sun to full shade depending on variety.
• Most soils suit them — avoid waterlogged ground.
• Plant in spring or autumn for best establishment.
• Allow space to spread — most reach 30–60cm across.

Seasonal care

After the main flush of flowers in summer, cutting the whole plant back by about half encourages a second flush of growth and often a second wave of flowers. This "Chelsea chop" also tidies up the plant and prevents it sprawling untidily. In autumn, leave the foliage to die back naturally — it provides some insulation for the crown. In spring, remove any dead material and a light top-dressing of compost or balanced fertiliser is beneficial but not essential.

Dividing and propagating

After three to four years, clumps may become congested and flower less well. Lift the whole plant in autumn or spring, divide it into smaller sections each with roots and shoots, and replant at the same depth. This is also the easiest way to make more plants for free. Hardy geraniums also set seed freely and self-seed around the garden — a property you can encourage or manage depending on preference.