Rozanne cranesbill

Sun

Full sun to partial shade; afternoon shade helps in hot summers.

Water

Keep evenly moist while establishing. Once established, water deeply during prolonged dry spells; flowering slows if the soil becomes too dry.

Soil

Well-drained soil enriched with compost; tolerates clay, loam and sandy soils, and a broad pH range, provided drainage is adequate.

Height

1.5-2 ft (0.45-0.6 m)

Spread

2-3 ft (0.6-0.9 m)

Flowers

Violet-blue flowers with white centres and purple veins from early summer into autumn, often until frost.

Foliage

Green, softly hairy, deeply lobed leaves, sometimes mottled with lighter green; foliage may turn reddish in autumn before dying back.

Growth

Moderate to fast during the growing season.

Care needed

Low

• Pollinators
• Deer resistant
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Easy

Toughness

Very tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   1 ft (0.3 m)

2. After 1 year

   1.3 ft (0.39 m)

3. After 2 years

   1.6 ft (0.49 m)

4. After 3 years

   1.7 ft (0.53 m)

   full size

About 2 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Safe

Growth rate

Fast

• Water newly planted clumps whenever the upper soil begins to dry, keeping the root zone moist but not saturated.
• Apply a thin layer of compost in spring; avoid heavy nitrogen feeding, which encourages sprawling leafy growth.
• Mulch around the plant to conserve moisture, keeping mulch clear of the crown.
• Allow space for trailing stems and redirect them away from small neighbouring plants; staking is usually unnecessary.
• Divide established clumps in spring only if they become crowded or need moving; regular division is not essential.

Pruning. Remove dead foliage in late winter or early spring before new growth develops. If growth becomes untidy in summer, shorten sprawling stems or shear the clump back and water it to encourage fresh growth; routine deadheading is unnecessary.

Late winter

Clear away dead stems and leaves, taking care not to damage emerging shoots.

Early spring

Plant or move clumps when the soil is workable; divide established plants if needed.

Spring

Apply compost and refresh mulch, leaving the crown uncovered.

Early summer

Guide spreading stems between neighbours and away from paths or low-growing plants.

Midsummer

Water during dry spells; trim tired or sprawling growth if flowering and appearance decline.

Autumn

Leave healthy foliage until it dies back and check that winter rain can drain freely.

• Plant along border edges where flowering stems can spill over paving without blocking the route.
• Weave between shrub roses to cover bare lower stems and extend colour beyond the main rose flush.
• Repeat through mixed perennial borders with salvias and ornamental grasses for a continuous blue thread.
• Use beneath open, sunlit shrubs as seasonal groundcover, leaving space around smaller plants.

Garden styles it suits: English country, Cottage garden, New perennial (prairie), Pollinator garden, Low-maintenance and Blues and silvers.

Plant it with: Shrub roses, Hardy salvias, Lady's mantle, Coneflowers, Feather reed grass and Japanese anemones.

Wildlife: The open flowers provide nectar and pollen for bees and other visiting insects. This sterile hybrid does not provide a useful seed crop for birds.

• Slugs and snails may damage young shoots: check emerging growth, remove pests by hand and use iron-phosphate bait according to the label if needed.
• Powdery mildew can develop during dry, stressed conditions: water the root zone, improve air circulation and remove badly affected foliage.
• Crown or root rot in waterlogged soil: improve drainage or move the plant to a raised position; avoid keeping the crown wet.
• Sparse flowers and floppy growth in deep shade: move to a brighter position and avoid excessive feeding.

Not known to be toxic to cats, dogs, horses or people; no part is established as poisonous. It is an ornamental rather than a food plant. Do not confuse hardy Geranium with Pelargonium, also commonly called geranium, which can be toxic to pets.

• Johnson's Blue cranesbill (Geranium 'Johnson's Blue')

  Usually has a much shorter main flowering period in late spring and early summer, with blue flowers lacking Rozanne's large, contrasting white centre.

• Bloody cranesbill (Geranium sanguineum)

  Generally forms a lower, tighter mound with more finely divided leaves and pink, magenta or white flowers rather than Rozanne's violet-blue blooms.

Geranium comes from the Greek geranos, meaning crane, referring to the beak-shaped fruits characteristic of the genus.

Propagation. This sterile hybrid does not come from seed. Propagate by careful spring division or suitable basal cuttings; check current plant breeders' rights or patent restrictions in your country before propagating.

Accepted botanical name

Geranium

Sources: GBIF (CC BY 4.0). The care and design notes are LandscapeGPT's own.