Overview
Petrocosmea flaccida is a matforming alpine rockery in the genus Petrocosmea, part of the Gesneriaceae family, with evergreen foliage. Petrocosmea flaccida grows best in partial shade, and tolerates loam soils and neutral pH. Its UK hardiness is rated H2. Suggested uses include patio and container plants.
About
Petrocosmea flaccida is a cultivar of the genus Petrocosmea, which comprises evergreen perennials forming low mats with thick, sometimes fuzzy, lanceolate or rounded leaves. This matforming plant produces small clusters of five-lobed, tubular to bell-shaped flowers in spring and summer. It thrives best in partial shade with a sheltered aspect, favouring north, east, or west-facing positions. Preferring fertile, well-drained loam soil with neutral pH, it is suitable for patio and container planting. This cultivar is hardy to UK zone H2 and can be propagated by seed or leaf cuttings.
Growing conditions
Best soil and position for Petrocosmea
- Sunlight
- Partial shade
- Soil type
- Loam
- Soil pH
- Neutral
- Soil moisture
- Well-drained
- Aspect
- North-facing, East-facing, West-facing
- Exposure
- Sheltered
- UK hardiness
- H2
Plant details
Petrocosmea flaccida size, habit and characteristics
- Plant type
- Alpine Rockery
- Habit
- Matforming
- Foliage
- Evergreen
- Suggested uses
- Patio and container plants
Care notes
Pruning and caring for Petrocosmea flaccida
- Propagation
- Seed, leaf cuttings
- Pest resistance
- Susceptible to slugs, snails, aphids, glasshouse whitefly, mealybugs, scale insects, tarsonemid mites
- Disease resistance
- Susceptible to mildew, crown, leaf, stem, and root rots
Frequently asked questions
Where is the best place to plant Petrocosmea flaccida?
Petrocosmea flaccida prefers partial shade. It suits sheltered positions.
What soil does Petrocosmea flaccida need?
Petrocosmea flaccida grows best in loam soil. It prefers neutral soil. Aim for soil that stays well-drained.
Is Petrocosmea flaccida hardy in the UK?
Petrocosmea flaccida has an RHS hardiness rating of H2, meaning it is tender, tolerating 1–5°C, and needs frost-free protection over winter.
How do I propagate Petrocosmea flaccida?
Seed, leaf cuttings.
More in the Petrocosmea genus
- Petrocosmea kerriiKerr’s petrocosmea
- Petrocosmea 'Rosemary Platz'petrocosmea 'Rosemary Platz'
- Petrocosmea rosettifolia C.Y. Wu ex H.W.L.