How to grow Sea Holly in the UK
Eryngium
Sea Holly (Eryngium) is a flower that grows well in UK gardens. Metallic blue spiky stunner. Hates wet feet. 'Big Blue' is the most intense colour. This guide covers when and how to sow Sea Holly, the soil and position it likes, watering and feeding, companion planting, and when to harvest.
When to sow & grow Sea Holly
Sowing and harvest window through the year (UK):
Jan | Feb | Mar | Apr Plant | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
Soil, position & care
- Soil
- Fertile, moisture-retentive but free-draining soil
- Soil pH
- 6.0–7.5
- Position
- Sun or part shade depending on species
- Sowing depth
- Plant at the same depth as the pot
- Spacing
- 30–60 cm apart
- Sowing
- Plant container-grown stock spring or autumn; divide established clumps in spring
- Growing
- Water well the first season until established; mulch in spring
- Harvest & upkeep
- Cut back faded foliage in late autumn or early spring; divide every 3–4 years
- Watch for
- Slugs and snails on new shoots; otherwise robust
Companion planting for Sea Holly
No specific companion notes for this plant.
Add Sea Holly to your free 12-month plan and get watering & sowing reminders — no sign-up needed.
Sea Holly FAQs
How much sun does Sea Holly need?
Sea Holly prefers full sun (6+ hrs direct).
When should I plant Sea Holly in the UK?
In the UK, plant Sea Holly in April. Planting in this window gives the roots time to establish before the plant is asked to grow away.
Is Sea Holly easy to grow?
Moderate. Metallic blue spiky stunner. Hates wet feet. 'Big Blue' is the most intense colour.