About
Petrorhagia saxifraga, the tunic flower, is a low-growing, mat-forming, hardy perennial alpine with small, thin, evergreen leaves. From late spring to late summer it produces a long succession of small, white or pale-pink flowers above the foliage. An excellent plant for cascading over walls, edging paths or covering green roofs.
About the genus
Petrorhagia are slender annuals and perennials with narrow, grass-like foliage and small clusters of pink, lilac or white, dianthus-like flowers in summer. Grown in sunny, well-drained positions.
Growing conditions
SunlightFull sun
Soil typeLoam, Sand
Soil pHAcid, Alkaline, Neutral
Soil moistureWell-drained
AspectSouth-facing, West-facing
ExposureExposed, Sheltered
UK hardinessH4
Plant details
Plant typeHerbaceous Perennial, Alpine Rockery
HabitMatforming
FoliageEvergreen
HeightUp to 10 cm
Spread0.1-0.5 metres
Time to full height2-5 years
Suggested usesCity and courtyard gardens, Cottage and informal garden, Gravel garden, Rock garden
Native toS & C Europe
Care notes
CultivationGrows best in poor to moderately fertile well-drained soil in full sun. Drought resistant once established
PruningCut back after flowering to encourage a second flush of flowers
PropagationSow from seed in spring or autumn in pots with free-draining seed compost. Harden off in a coldframe or greenhouse and plant out when risk of frost has passed.
Pest resistanceMay be susceptible to slugs and snails
Disease resistanceGenerally disease-free