How to plant and care for Sea Holly (Eryngium)

Eryngium × zabelii 'Big Blue'

🌸 Flower 🔁 Perennial

Spiky, metallic-blue thistle-like flowers with a silver ruff, from July to September. Loved by bees and wonderful dried. Thrives in poor, dry soil.

When to plant and care for it

JanFebMarAprMayJunJulAugSepOctNovDec

Flowers

Timed for a typical UK garden (last frost mid-April). The app uses your own town's frost dates.

On planting day
Plant
Plant at the same depth as it was in its pot, 45 cm apart, and firm in.
0–1 days after “Plant”
Water In Well
Give a full can of water, then keep moist for the first few weeks while roots establish.
7–14 days after “Water In Well”
Mulch Around the Base
Spread 5 cm of compost or bark around the plant, keeping it off the stems.

March
Cut Back Old Growth
Leave the seed heads for winter interest, then cut old stems down in early spring.
July
In Flower
Steely blue flowers — bees love them.