Cranesbill: which species where, summer trim and propagation

In short: The cranesbill (Geranium) is an undemanding hardy perennial for sun or shade, depending on the species. It tolerates most soils except waterlogged ones. After the first flowering in June to July, cut it to the ground; it regrows and often flowers again. Clumps are divided in spring or autumn. A cranesbill is not a pelargonium (geranium of window boxes).

Cranesbills are perennials that gardeners plant when they want to fill a bed, and then discover they want them everywhere. They grow in shade under trees, on a sunny rockery and in a front garden, suppress weeds, tolerate drought and have almost no diseases. They are popularly called stork's bills after their elongated beaked fruits.

As there are over 400 species, success depends mainly on choosing the right one for the spot. Below is an overview of the most commonly used species, the planting procedure, the summer trim, propagation and sowing from seed.

Cranesbill or pelargonium?

In shops the two plants get mixed up because of the English word "geranium", which is popularly used for pelargoniums too.

• Cranesbill (Geranium) is a hardy perennial that overwinters outdoors. It flowers with smaller, regular flowers.
• Pelargonium (Pelargonium) comes from southern Africa, does not tolerate frost and is grown in window boxes, kept indoors over winter. Its cultivation is covered in the article pelargoniums (geraniums).

Both belong to the same family, but they are grown quite differently. Do not apply advice for pelargoniums to cranesbills, or the other way round.

Which cranesbill where

For dry shade under trees, where other perennials do not thrive, bigroot cranesbill is the most reliable. Other plants for shady places are described in the article which plants suit the shade.

Planting

1. Timing: spring is the safest; on heavy clay soil always plant in spring. Plants from containers can also be planted in early autumn.
2. Soil: cranesbills tolerate most garden soils, minding only standing water in winter. Add compost to poor soil and lighten heavy soil with sand.
3. Spacing: according to the final width on the label, for ground-cover species usually 30–45 cm, for large clumps up to 60 cm. For a continuous stand allow 5–7 plants per m².
4. Depth: the same as the plant grew in the pot. Water thoroughly and do not let it dry out until it roots.

Summer trim: a second flowering for free

Many cranesbills "fall apart" after the first flowering in June to July: the stems flop, the middle of the clump is empty and the leaves fade. The solution is radical, but it works.

1. When most of the flowers have finished, cut the whole clump with shears or a sickle to 5–10 cm above the ground.
2. Leave only young basal leaves, if there are any.
3. Water generously, and in dry weather keep watering for another 2–3 weeks.
4. In 2–3 weeks the clump regrows with fresh leaves and, in most species and cultivars, a second, smaller wave of flowers comes.

Long-flowering cultivars such as ‘Rozanne’ do not need this treatment; it is enough to shorten the sprawling shoots. Bigroot cranesbill does not need cutting, as it holds a tidy shape all season. You will find other perennials with long flowering in the article inspiration: long-flowering perennials.

Dividing and cuttings

Divide clumps that thin out in the middle in spring as they shoot or in autumn. Dig them up, divide them with a spade or by hand into pieces with roots and buds and replant immediately. Ground-cover species (bigroot, Endres's) can be divided at any time during the season; just separate a rooted piece of rhizome.

Cultivars are always propagated by division or cuttings, because seeds do not produce identical plants. Sterile varieties, for example ‘Rozanne’, do not set seed at all.

Cranesbill from seed

It is worth growing mainly botanical species from seed, such as meadow, bloody or dusky cranesbill. Seeds of cultivars give plants different from the parent.

• Collecting: ripe fruits fling the seeds violently into the surroundings. Slip a paper bag over ripening fruits, or collect them as soon as they start to turn brown.
• Sowing: the seeds of many species germinate unevenly and better after winter cold. The simplest is to sow them in autumn in a tray or pots, cover lightly and leave outdoors. They come up in spring.
• Spring sowing: first chill the seeds for 4–6 weeks in moist compost in the fridge, then sow at 15–20 °C.
• Flowering: seedlings usually flower only in the second year.

Meadow and wood cranesbills also suit flowery meadows very well; how to establish them is described in the article flower meadow. Do not collect seeds or plants in protected areas, and leave rare species in the wild; for example, the shining cranesbill is critically endangered in the Czech Republic.

Diseases and pests

• Powdery mildew appears in a dry summer as a white coating on the leaves. Watering in drought, the summer trim and airy spacing help. More in the article powdery mildew.
• Vine weevil mainly damages plants in containers. The larvae in the compost eat the roots and the plant suddenly wilts.
• Slugs occasionally nibble young spring leaves; they usually do not harm mature clumps.

Frequently asked questions

When should I cut cranesbills?

After the first flowering in June to July, cut the clump to 5–10 cm above the ground and water. In 2–3 weeks it regrows and often flowers again. Tidy the dry remains in autumn or spring.

Does a cranesbill tolerate shade?

It depends on the species. Bigroot and dusky cranesbills also grow in shade, bigroot even in dry shade under trees. Meadow and bloody cranesbills need sun.

What is the difference between a cranesbill and a pelargonium?

A cranesbill (Geranium) is a hardy perennial for the bed. A pelargonium (Pelargonium) does not tolerate frost and must be taken indoors over winter. The two plants are related, but they are grown differently.

When should I divide cranesbills?

In spring as they shoot or in autumn. Ground-cover species can also be divided during the season if you water the separated piece well.

How do I sow cranesbills from seed?

Most easily in autumn in trays that you leave outdoors over winter. The seeds need cold and come up in spring. Grow only botanical species from seed; cultivars do not come true.

Is a cranesbill long-lived?

Yes, garden cranesbills are hardy perennials that last many years in one spot. It is enough to rejuvenate them by division once every few years.

Recommended products

• Xcellent garden shears, large – for the summer trim of the whole clump after flowering.
• Pointed spade SOLID FISKARS – for dividing old clumps.
• Planting trowel – for planting divided pieces and small plants.
• Seed compost 5 l (suppressive) – for the autumn sowing of botanical species in trays.

Sources

• Royal Horticultural Society: How to grow hardy geraniums
• Decree No. 395/1992 Coll., Annex II: strictly protected plant species

Updated: 27 September 2026