Perennial

Geranium Rozanne (‘Gerwat’)

Rozanne cranesbill

Also known as: Geranium 'Rozanne'

A famously long-flowering hardy geranium with violet-blue, white-eyed flowers from early summer to autumn.

  • Full sun, Partial shade
  • 50–60 cm (20–24 in)
  • 0.6–1 m (2–3 ft)
  • H7 · Zone 4
  • June–October
  • Deciduous
  • RHS Award of Garden Merit

At a Glance

Sun Full sun, Partial shade
Height 50–60 cm (20–24 in)
Spread 0.6–1 m (2–3 ft)
Hardiness H7 · Zone 4
Flowers June–October
Soil Chalk, Clay, Loam, Sand
Moisture Moist well drained
Habit Mound-forming, Sprawling, Spreading
Water Moderate
Maintenance Easy

Growing Conditions

Min. Temperature -25°C (-13°F)
pH Range 5.5–8
Fertility Average
Drainage Free Draining

Aspect Suitability

  • North-facing
  • East-facing
  • South-facing
  • West-facing

Soil Tolerance

  • Clay
  • Chalk
  • Sandy
  • Loam
  • Acid
  • Neutral pH
  • Alkaline

Foliage

Persistence Deciduous
Colour Green
Leaf shape / texture palmately_lobed
  • Autumn colour

Foliage interest: April–November

Seasonal Timeline

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Flowering
Foliage
Propagate
  • Flowering Jun Jul Aug Sep Oct
  • Foliage Apr May Jun Jul Aug Sep Oct Nov
  • Propagate Mar Apr

How to propagate

Ways to grow more Rozanne cranesbill: the usual steps for each method.

Division Mar–Apr Easy

You'll need: A garden fork or spade (two forks back to back help with big clumps) and a sharp knife.

  1. Water the plant well the day before.
  2. Dig up the whole clump with a fork, keeping as much root as you can.
  3. Split it into pieces about the size of your fist, each with healthy roots and shoots: pull them apart by hand, or cut tough clumps with a knife or spade.
  4. Throw away any old, woody middle.
  5. Replant the pieces straight away at the same depth, and water them in well.
How long
Settles in within a few weeks.
It's worked when
Fresh new growth within a few weeks.
Then
Water in dry spells for the rest of the season.
Softwood cuttings Apr Takes a little care

You'll need: Clean, sharp secateurs or a knife, small pots, gritty compost (half compost, half grit or perlite), a plastic bag, and rooting powder if you have it.

  1. Early in the morning, cut soft, non-flowering shoot tips about 5 to 10 cm long, and keep them in a plastic bag so they don't wilt.
  2. Trim each one just below a leaf joint and take off the lower leaves, leaving two or three at the top.
  3. Dip the cut end in rooting powder if you have some.
  4. Push them into the edge of a pot of gritty compost so their leaves don't touch, and water them in.
  5. Cover with a clear bag or put them in a propagator, somewhere bright but out of direct sun.
How long
Roots in about 3 to 6 weeks.
It's worked when
New growth at the tips, and roots showing through the pot's holes.
Then
Pot each one up on its own and grow it on. Keep young plants frost-free through their first winter.

A protected (PBR) variety, so propagation is for your own garden only. Divide clumps in early spring, or take basal cuttings as shoots appear.

Maintenance Calendar

  • Mar Clear away last year's dead stems as new growth emerges, giving fresh shoots light and air
  • Mar Divide large clumps every few years in early spring if you want more plants
  • Jul If it sprawls or looks tired in midsummer, cut long stems back by half to bring a fresh flush of leaves and flowers
  • Aug Water in long dry spells, which helps prevent powdery mildew on the leaves

Garden Design

Works well in: Cottage, Modern / Contemporary, Wildlife-friendly, Woodland / Shade

Let it weave between roses and shrubs, spill over a wall or pot edge, or fill gaps at the front of a border; one plant covers a wide area by late summer.

Companion planting: Roses, Alchemilla, Grasses, Lime-green foliage

Wildlife Value

  • Bees
  • Butterflies
  • Other pollinators
  • Beneficial insects
  • RHS Plants for Pollinators

Safety

Not known to be toxic to people or pets.