About

In summer it produces spherical heads of violet blue flowers. A semi-evergreen perennial forming tufts of linear leaves to 15cm long. Site in a sunny rock garden or at the front of a border.

About the genus

A genus of flowering herbaceous perennials, native to Europe and Morocco. Foliage is alternate and petiolate, varying in shape between cultivars. Flowers are produced in dense panicles with narrow, five-lobed corolla and are mostly purple, but sometimes pale blue, white or pink

Growing conditions

SunlightFull sun
Soil typeChalk, Loam, Sand
Soil pHAcid, Alkaline, Neutral
Soil moistureMoist but well-drained, Well-drained
AspectSouth-facing, West-facing
ExposureSheltered
UK hardinessH6

Plant details

Plant typeAnnual Biennial
HabitTufted
FoliageSemi evergreen
Height0.1-0.5 metres
Spread0.1-0.5 metres
Time to full height2-5 years
Suggested usesRock garden
Native toAlps

Care notes

CultivationGrow in moderately fertile, well-drained soil in full sun
PruningNo pruning required
PropagationPropagate by sowing seed in a cold frame in containers in autumn
Pest resistanceMay be susceptible to slugs and snails
Disease resistanceGenerally disease-free