Regal geranium

Sun

Full sun in cool climates; morning sun and afternoon shade in hot climates.

Water

Water thoroughly when the surface of the compost feels dry, then let excess water drain. Keep barely moist during cool winter storage.

Soil

Well-drained, moderately fertile soil; use a free-draining potting mix in containers.

Height

1-3 ft (0.3-0.9 m)

Spread

1-2 ft (0.3-0.6 m)

Flowers

Mainly spring to early summer, sometimes repeating in cool autumn weather; white, pink, salmon, red, purple or burgundy, often bicoloured with dark markings.

Foliage

Evergreen. Rounded to broadly heart-shaped green leaves with toothed edges and a slightly rough texture.

Growth

Moderate

Care needed

Medium

• Low allergen

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

Difficulty

Moderate

Toughness

Fairly 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 (0.4 m)

3. After 2 years

   1.6 ft (0.5 m)

4. After 3 years

   2 ft (0.6 m)

   full size

About 3 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

Toxic

Growth rate

Moderate

• Use containers with drainage holes, and empty saucers after watering.
• Water the compost rather than the flowers and leaves.
• Feed actively growing, flowering plants every two weeks with a balanced liquid fertiliser at the label rate.
• Remove spent flower stems and yellowing leaves promptly.
• Bring plants under cover before frost; overwinter in bright, airy conditions, ideally around 7-13°C.
• Allow cool, frost-free nights before the flowering season; consistently warm conditions can reduce bud formation.

Pruning. Pinch young shoots to encourage branching. After the main flowering flush, shorten leggy stems by about one-third, cutting just above a healthy leaf joint.

Late winter

Check overwintered plants for pests and remove dead leaves; increase watering gradually as growth resumes.

Spring

Repot crowded plants into fresh, free-draining compost and begin feeding once growth is active.

Late spring

Harden plants off gradually and place outdoors once frost risk has passed.

Summer

Deadhead regularly, check containers for dryness and provide afternoon shade during hot weather.

Late summer

Take non-flowering stem cuttings and lightly shorten plants that have finished their main flowering flush.

Autumn

Move plants under cover before frost, reduce watering and stop feeding as growth slows.

Winter

Keep plants bright, cool and frost-free; water sparingly without letting the root ball dry out completely.

• Use a single plant in a terracotta pot beside a sunny doorway for a concentrated display of flowers.
• Group containers on a sheltered patio, combining flower colours with silver foliage plants.
• Place in window boxes with trailing bacopa or lobelia where watering and deadheading are easy.
• Use as temporary spring-to-summer colour at the front of a sheltered border in cool-summer gardens.

Garden styles it suits: Modern courtyard, Traditional, Victorian, Cottage garden, Mediterranean and Small-space.

Plant it with: Bacopa, Trailing lobelia, Sweet alyssum, Dusty miller and Diascia.

Wildlife: Flowers may attract some visiting insects, but this is not a dependable nectar plant; nearby single-flowered plants provide better support for pollinators.

• Whitefly and aphids: inspect leaf undersides, isolate affected pots and treat with insecticidal soap labelled for the pest, repeating as directed.
• Grey mould: remove affected flowers and leaves, improve airflow and avoid wetting foliage or leaving dead petals on the plant.
• Root rot: prevent waterlogging with drainage holes and free-draining compost; discard badly rotted plants.
• Few flowers during hot weather: provide afternoon shade and avoid excessive nitrogen feeding; flowering may resume when nights become cooler.

Pelargoniums are toxic to cats and dogs if chewed or eaten; leaves, stems and flowers can cause vomiting, reduced appetite and skin irritation. Horse toxicity is not well established, so do not allow grazing or feed clippings. Serious poisoning in people is not generally expected, but sap may irritate sensitive skin and the plant should not be treated as edible.

• Zonal geranium (Pelargonium × hortorum)

  Usually has rounder leaves, often marked with a dark horseshoe-shaped zone, and rounded heads of smaller flowers rather than the regal's large, often blotched blooms.

• Ivy-leaved geranium (Pelargonium peltatum)

  Has trailing stems and smoother, fleshy, ivy-shaped leaves; regal geranium is generally upright with rougher, toothed foliage.

• Hardy geranium (Geranium species and hybrids)

  Usually has five similar-sized petals and deeply divided leaves, and many survive freezing winters; regal geranium has unequal petals and needs frost protection.

Pelargonium comes from the Greek word for stork, referring to the beak-shaped fruit, while regal refers to the plant's large, richly coloured flowers.

Propagation. Take non-flowering stem cuttings in late summer, remove the lower leaves and insert into a clean, free-draining propagation mix. Keep in bright indirect light with gentle moisture, not saturated compost; named cultivars do not reliably come true from seed.

Accepted botanical name

Pelargonium domesticum

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