Plant care
Pelargonium 'Rollisson's Unique' (Rollisson's Unique pelargonium) care
Pelargonium 'Rollisson's Unique'
Also called Rollisson's Unique pelargonium, Unique geranium.
Watering rhythm
5-7days
When the top 2-3 cm of compost is dry, about every 5-7 days in summer
Light
Direct sun (at least 4-6 hours)
Soil
Free-draining loam-based compost
Humidity
30-50%
Temp
10-24°C
Pet safety
Toxic to pets
Mature size
Reaches 60-90 cm tall and 45-60 cm wide if unpruned
Care at a glance
Light
Pelargonium 'Rollisson's Unique' needs sun on the leaves, not just bright ambient room light. Full sun for the best flowering and sturdy growth; at least 6 hours of direct light. Tolerates a little afternoon shade in very hot climates but flowers less in dull positions. A south or west-facing windowsill in the northern hemisphere is the default; anywhere else, expect the plant to stretch and pale out within a season.
Watering
Water pelargonium 'rollisson's unique' when the top 2-3 cm of compost is dry, about every 5-7 days in summer. The actual day count varies with pot size, light, and season — the finger test (or lifting the pot to feel its weight) is more reliable than a fixed calendar. Empty any drainage saucer afterwards so the pot isn't sitting in water. Water thoroughly and let the surface dry between waterings; Uniques are vigorous and drink more in heat. Reduce watering in winter to keep the rootball just moist and prevent rot.
Soil and pot
Pelargonium 'Rollisson's Unique' grows best in free-draining loam-based compost. John Innes No. 2 or No. 3 with added grit or perlite for the larger rootball. Neutral to slightly alkaline; never waterlogged. 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 'Rollisson's Unique' sits happiest at around 30-50% humidity and 10-24°C (50-75°F). Average room or greenhouse humidity is fine. Good airflow is important to prevent botrytis and rust on the dense, leafy growth. 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 'rollisson's unique' sparingly. Feed every 2 weeks from spring to early autumn with a high-potash liquid feed to fuel its prolific flowering; this vigorous type appreciates regular feeding. Stop over winter. 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 'rollisson's unique' in the Growli community. Each is annotated with the most common cause so you know where to start.
- Sparse flowering — Too little sun or no pruning leads to leafy, flower-shy plants. Give full sun and prune back in late winter to encourage flowering wood.
- Legginess — Uniques naturally grow tall and can flop; prune hard in early spring and pinch shoots to build a bushy framework.
- Geranium rust — Brown pustules under the leaves in damp conditions. Remove affected foliage and improve ventilation.
- Whitefly and aphids — Thrive on the lush growth under glass; inspect regularly and treat early with insecticidal soap or biocontrols.
Propagation
From softwood stem cuttings in spring or late summer; this Unique cultivar roots readily from 10 cm tip cuttings in gritty, free-draining compost with warmth. 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 'Rollisson's Unique' is toxic to pets. The ASPCA lists Geranium (Pelargonium species) as toxic to cats, dogs and horses, with geraniol and linalool as the toxic principles. Ingestion can cause vomiting, anorexia, depression and dermatitis. Site away from curious pets. 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 'Rollisson's Unique' care — frequently asked questions
What is the common name for Pelargonium 'Rollisson's Unique'?
Pelargonium 'Rollisson's Unique' is most commonly called Pelargonium 'Rollisson's Unique', but it is also known as Rollisson's Unique pelargonium, Unique geranium. The names refer to the same species, so care instructions for Pelargonium 'Rollisson's Unique' apply identically to anything sold as Rollisson's Unique pelargonium.
How much light does pelargonium 'rollisson's unique' need?
Pelargonium 'Rollisson's Unique' grows best in direct sun (at least 4-6 hours). Full sun for the best flowering and sturdy growth; at least 6 hours of direct light. Tolerates a little afternoon shade in very hot climates but flowers less in dull positions.
How often should I water pelargonium 'rollisson's unique'?
Water pelargonium 'rollisson's unique' when the top 2-3 cm of compost is dry, about every 5-7 days in summer. Water thoroughly and let the surface dry between waterings; Uniques are vigorous and drink more in heat. Reduce watering in winter to keep the rootball just moist and prevent rot. The finger-test (or lifting the pot to feel its weight) beats a fixed weekly calendar because pot size, light, and season all change how fast the soil dries.
Is pelargonium 'rollisson's unique' toxic to cats and dogs?
Pelargonium 'Rollisson's Unique' is toxic to pets. The ASPCA lists Geranium (Pelargonium species) as toxic to cats, dogs and horses, with geraniol and linalool as the toxic principles. Ingestion can cause vomiting, anorexia, depression and dermatitis. Site away from curious pets.
What USDA hardiness zone does pelargonium 'rollisson's unique' grow in?
Pelargonium 'Rollisson's Unique' is rated for USDA zone 9-11 (tender; overwinter under glass where frosts occur) and RHS hardiness H1c. Outside that range, grow it as a container plant that overwinters indoors before the first hard frost.
Pelargonium 'Rollisson's Unique' deep-dive guides
Every aspect of pelargonium 'rollisson's unique' care, each with its own calibrated guide:
- Pelargonium 'Rollisson's Unique' watering schedule
- Pelargonium 'Rollisson's Unique' light requirements
- Best soil mix for pelargonium 'rollisson's unique'
- Pelargonium 'Rollisson's Unique' fertilizing guide
- When to repot pelargonium 'rollisson's unique'
- How to propagate pelargonium 'rollisson's unique'
- Pelargonium 'Rollisson's Unique' growth rate & size
- Pelargonium 'Rollisson's Unique' cold hardiness
- Pelargonium 'Rollisson's Unique' temperature & humidity
- Is pelargonium 'rollisson's unique' toxic to cats & dogs?
- Is pelargonium 'rollisson's unique' toxic to cats?
- Is pelargonium 'rollisson's unique' toxic to dogs?
- Getting pelargonium 'rollisson's unique' to bloom
Featured in these plant shortlists
Pelargonium 'Rollisson's Unique' qualifies for 6 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:
- Best trailing & climbing houseplants — Vining and trailing houseplants for shelves, hanging pots, and moss poles — selected by growth habit.
- 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 full sun — Houseplants that want direct sun — the species for a hot south or west-facing windowsill where shade-lovers scorch.
- 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.
- Best fast-growing houseplants — Houseplants documented as fast or vigorous growers — quick to fill a pot, cover a pole or trail down a shelf.
- Browse all 29 plant shortlists — pet-safe, low-light, drought-tolerant and more
Related guides
Pelargonium 'Rollisson's Unique' is also commonly called Rollisson's Unique pelargonium or Unique geranium.