Planum

Eryngium planum

£6.00

Plant profile · availability to be confirmed

Discover the striking Sea Holly (Eryngium Planum), a hardy perennial boasting vibrant blue flowers and foliage that blooms from July through September—perfect for coastal, cottage, and wildlife gardens. This drought-resistant, low-maintenance clump-former thrives in full sun with free-draining soil and reaches an impressive 80cm height, making it ideal for cutting gardens and naturalistic landscapes. At just £6 with 10% going to organic initiatives, it's an exceptional value for a versatile, hardy plant that establishes in 1-2 years.

A CLOSER LOOK

Plant details.

LifecyclePerennial
HabitClump-forming
Foliage typeDeciduous

Suitability: Borders, Coastal gardens, Cottage gardens, Gravel gardens, Wildlife gardens, City and courtyard gardens
Light: Full sun
Soil moisture: Free draining
Soil acidity: Neutral, Acid, Alkaline
Soil type: Chalk, Loam, Sandy
Hardiness: H5 [-15 to -10ºC] Hardy | Cold winter
Time to maturity: 1–2 Years
Exposure: Sheltered
Mature height: 0.5–1 m
Mature spread: 0.1–0.5 m
Foliage colour: Blue, Green
Flower colour: Blue
Genus: Sea Holly | Eryngium
Aspect: South, West
Drought resistance: Drought Resistance

Through the seasons

A year at a glance

Flowering

Jul–Sep

In leaf

Mar–Oct

Sow indoors

Jan–Apr

Filled months show recorded activity. Timing can vary with climate and growing conditions; unfilled months are not recorded.

GETTING TO KNOW YOUR PLANT

A happy plant
starts here.

Every plant grows a little differently. Your new arrival’s shape and size may vary from the photograph.

Growing conditions+

Position: Full sun. Soil: Well-drained.

Winter hardiness+

RHS rating: H5 (UK growing conditions). See the source profile for cultivation advice.

Plant information sources+

Growing details checked against the sources below. Ultimate size depends on growing conditions.

RHS · Eryngium planum

THE GREENHOUSE JOURNAL

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