About
Seven Seas' is a clump-forming perennial to 90cm with rounded basal leaves. Upright, branching stems bear deeply-lobed, blue-tinged, spiny leaves and small, dark blue, terminal flower-heads with narrow, spiny bracts in summer and early autumn.
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
AspectSouth-facing, West-facing
ExposureSheltered
UK hardinessH5
Plant details
Plant typeHerbaceous Perennial
HabitClump forming
FoliageDeciduous
Height0.5-1 metres
Spread0.1-0.5 metres
Time to full height1-2 years
Suggested usesCity and courtyard gardens, Cottage and informal garden, Coastal
Care notes
CultivationGrow in dry, well-drained poor to moderately fertile soil in full sun, with protection from winter wet
PruningTidy plants after flowering; ideal for flower arranging - cut the stems before the flowers are fully open
PropagationPropagate by division during spring, although they may be slow to re-establish, or insert root cuttings in late winter
Pest resistanceMay be susceptible to leaf and bud eelworms, and slugs and snails
Disease resistanceMay be susceptible to root rot and powdery mildews