A picture of a Sea Holly

Sea Holly

Eryngium maritimum

Also known as

Seaside Eryngo, Eryngo, Maritime Eryngo, Seaside Coyote-Thistle, Sea holly, Sea eryngium

Eryngium maritimum MichaD 1 by Michael Apel (CC BY-SA 3.0)

Full Sun
Easy care
Light watering
Frost Hardy

H7-H4

RHS hardiness

-20°C

Minimum temperature

Expected size

Height
Spread

50cm

Max

50cm

10cm

Min

10cm

5 years to reach maturity

Flowering

  • spring
  • summer
  • autumn
  • winter

This plant has no fragrance

More images of Sea Holly

Eryngium maritimum-01 (xndr)
Eryngium maritimum plavi kotrljan 0809 1
Eryngium maritimum Cala Sinzias
Eryngium maritimum 1b

Sea Holly Overview

This evergreen perennial sea holly forms a lovely mound from which upright to decumbent stems bearing stiff, spiny, blue- to grey-green leaves appear. From summer into autumn it produces cone-like, blue flowers which can be cut for floral arrangements or left to provide winter interest. The blue colour can intensify with cold weather. This species can be used to create decorative borders, beds, pot plants, containers and landscapes. Be aware, they can overgrow and invade areas quickly, and with every little root that stays behind in the soil growing into a new plant, they are tricky to remove from an area!

How to harvest Sea Holly

Generally not harvested.

How to propagate Sea Holly

Division

Clumps in autumn

Cuttings

Root

Seed

Special features of Sea Holly

Attractive flowers

Attracts useful insects

Autumn colour

Other uses of Sea Holly

Wildflower/meadow Summer/Autumn interest. Suitable for coastal conditions.