Pelargonium x domesticum 'Carisbrooke' (Carisbrooke regal pelargonium) care

Light

Bright but filtered. Pelargonium x domesticum 'Carisbrooke' burns within days in unfiltered south-facing summer sun, and stops growing within months in deep shade. Bright light with some direct morning sun gives the best bloom and colour; shield from intense midday summer sun, which scorches the foliage and shortens the flowering period. If you only have a south window, set the plant back 1.5 m or hang a sheer curtain — both knock the intensity down into the right range.

Watering

Watering pelargonium x domesticum 'carisbrooke': when the top 2-3 cm of soil is dry, roughly every 5-7 days in growth. The number that matters isn't the day of the week — it's how dry the top 2-3 cm of the pot feels. A finger in the soil tells you more than a watering app. After every watering, tip the saucer. Water thoroughly and let the surface dry before the next; ease off after flowering and keep nearly dry in winter. Avoid wetting the foliage to limit fungal problems.

Soil and pot

Pelargonium x domesticum 'Carisbrooke' grows best in free-draining loam-based potting mix. A loam-based compost (such as John Innes No. 2) with added grit gives stability and drainage. Good drainage is vital to avoid black-leg. Neutral to slightly alkaline pH suits it. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Pelargonium x domesticum 'Carisbrooke' sits happiest at around 30-50% humidity and 10-21°C (50-70°F). Average to dry indoor air is fine; good ventilation is important because the dense regal foliage is prone to grey mould and rust in still, humid conditions. If you keep the room above 10 year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed pelargonium x domesticum 'carisbrooke' sparingly. Feed every 1-2 weeks with a balanced liquid feed in spring, switching to high-potash as buds form; stop feeding once flowering ends and through winter dormancy. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on pelargonium x domesticum 'carisbrooke' in the Growli community. Each is annotated with the most common cause so you know where to start.

• Short flowering season — Regals bloom in one main spring flush; a cool rest at 7-10°C over winter and bright spring light maximise the next display.
• Pelargonium rust — Brown pustules on leaf undersides spread in humid, crowded conditions; remove affected leaves and improve ventilation.
• Black-leg / stem rot — Blackening at the stem base from overwatering or cold, wet compost; water sparingly and use free-draining mix.
• Whitefly and aphids — Common under glass; they weaken growth and excrete sticky honeydew. Treat with insecticidal soap or biological controls.

Propagation

Take 8-10 cm softwood or semi-ripe cuttings in late summer from non-flowering shoots. Remove lower leaves, let the base callus, and root in gritty, just-moist compost at around 18°C; rooting takes 3-4 weeks. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Pelargonium x domesticum 'Carisbrooke' is toxic to pets. The ASPCA lists Pelargonium species (geranium) as toxic to cats, dogs and horses. Toxic principles are geraniol and linalool, with ingestion causing vomiting, anorexia, depression and dermatitis. Keep this plant away from pets that nibble foliage. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Pelargonium x domesticum 'Carisbrooke' deep-dive guides

Every aspect of pelargonium x domesticum 'carisbrooke' care, each with its own calibrated guide:

• Pelargonium x domesticum 'Carisbrooke' watering schedule
• Pelargonium x domesticum 'Carisbrooke' light requirements
• Best soil mix for pelargonium x domesticum 'carisbrooke'
• Pelargonium x domesticum 'Carisbrooke' fertilizing guide
• When to repot pelargonium x domesticum 'carisbrooke'
• How to propagate pelargonium x domesticum 'carisbrooke'
• Pelargonium x domesticum 'Carisbrooke' growth rate & size
• Pelargonium x domesticum 'Carisbrooke' cold hardiness
• Pelargonium x domesticum 'Carisbrooke' temperature & humidity
• Is pelargonium x domesticum 'carisbrooke' toxic to cats & dogs?
• Is pelargonium x domesticum 'carisbrooke' toxic to cats?
• Is pelargonium x domesticum 'carisbrooke' toxic to dogs?
• Getting pelargonium x domesticum 'carisbrooke' to bloom

Featured in these plant shortlists

Pelargonium x domesticum 'Carisbrooke' qualifies for 4 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

• Best plants for a north-facing window — Houseplants for a north-facing window: bright, even, indirect light and no scorching direct sun. Each pick verified against its documented light needs.
• Best flowering houseplants — Indoor plants grown for their blooms — selected from the flowering species in Growli’s plant-care library.
• Houseplants toxic to cats & dogs — The common houseplants the ASPCA lists as toxic to cats and dogs — the ones to keep out of reach, each with its symptoms and a safe alternative.
• Best houseplants for a cool room — Houseplants that tolerate cool conditions down to about 10°C — for an unheated spare room, hallway, porch or a home kept cool.
• Browse all 29 plant shortlists — pet-safe, low-light, drought-tolerant and more

Related guides

Pelargonium x domesticum 'Carisbrooke' is also commonly called Carisbrooke regal pelargonium or Martha Washington geranium Carisbrooke.

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