About
An erect, branching biennial with green foliage, and cone-like heads of blue flowers surrounded by spiny, silvery-white bracts appearing in summer.
About the genus
Eryngium can be annuals, biennials or perennials with simple or divided leaves, often spiny edged, and cone-like flower-heads often surrounded by an involucre of conspicuous spiny bracts
Growing conditions
SunlightFull sun
Soil typeChalk, Loam, Sand
Soil pHAcid, Alkaline, Neutral
Soil moistureWell-drained
AspectEast-facing, South-facing, West-facing
ExposureExposed
UK hardinessH6
Plant details
Plant typeHerbaceous Perennial
HabitClump forming
FoliageDeciduous
Height0.5-1 metres
Spread0.1-0.5 metres
Time to full height2-5 years
Suggested usesCoastal, Cottage and informal garden, Gravel garden, Wildlife gardens, Architectural
Care notes
CultivationGrow in dry, well-drained soil that is poor to moderately fertile. Full sun is essential. Tends to be a short-lived perennial but it self-seeds readily in the right conditions
PruningAlthough you can cut back flower stems after flowering the seedheads are a very attractive feature so are usually left over winter
PropagationPropagate by seed. Sow seeds onto moist but well-drained peat-free seed compost and cover lightly with vermiculite. Keep at a temperature of between 18-22°C
Pest resistanceMay be susceptible to leaf and bud eelworms, and slugs and snails
Disease resistanceMay be susceptible to root rot and powdery mildews