Eryngium × zabelii 'Big Blue'
sea holly [Big Blue]
An upright, herbaceous perennial to 75cm with spiky, highly-divided, silvery-green foliage. The stiff, branched stems are topped with blue, thimble-shaped flowerheads surrounded by a ruff of prickly, silvery-blue bracts
Synonyms
Eryngium × olivierianum 'Myersblue'Eryngium 'Big Blue'
see moreEryngium × zabelii 'Big Blue'
Eryngium × zabelii 'Myersblue'PBR
Eryngium × zabelii Big BluePBR
_8815.JPG)
Size
Ultimate height
0.5–1 metresTime to ultimate height
2–5 yearsUltimate spread
0.1–0.5 metresGrowing conditions
Moisture
Well–drainedpH
Acid, Alkaline, NeutralColour & scent
| Stem | Flower | Foliage | Fruit | |
| Spring | Green Grey Silver | |||
|---|---|---|---|---|
| Summer | Blue | Green Grey Silver | ||
| Autumn | Green Grey Silver | |||
| Winter |
Position
- Full sun
Aspect
South–facing or West–facing or East–facing
Exposure
Exposed or ShelteredDrought resistance
Yes Hardiness
H5Botanical details
- Family
- Apiaceae
- Native to GB / Ireland
- No
- Foliage
- Deciduous
- Habit
- Clump forming
- 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
- Name status
Trade
How to grow
Cultivation
Grow in dry, well-drained soil that is poor to moderately fertile. Full sun is essential as is protection from winter wet
Propagation
Propagate by root cuttings in late winter
Suggested planting locations and garden types
- Gravel garden
- Architectural
- City and courtyard gardens
- Coastal
- Cottage and informal garden
- Patio and container plants
- Prairie planting
- Banks and slopes
- Cut flowers
- Flower borders and beds
Pruning
Although you can cut back flower stems after flowering the seedheads are a very attractive feature so are usually left over winter
Pests
May be susceptible to leaf and bud eelworms
Diseases
May be susceptible to root rot and powdery mildews
Get involved
The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.