Eryngium

Eryngium planum

Blue Eryngo, Flat Sea Holly, Blue Glitter

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Flat Sea Holly (Eryngium planum) (14240745500) by Bernard DUPONT (CC BY-SA 2.0)
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A close up of some blue Eryngium planum flowers
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Flat Sea Holly (Eryngium planum) (14240745500) by Bernard DUPONT (CC BY-SA 2.0)
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Eryngium planum is a striking herbaceous perennial plant. It is used to create decorative borders, beds, pot plants, containers and landscapes. Excellent for cut or dried flower arrangements. The blue colour intensifies with cold weather. 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! This species is part of the Royal Horticultural Society “Plants for Pollinators” initiative to showcase plants which support pollinator populations by providing ample amounts of nectar and/ or pollen. A great choice for encouraging pollinating insect wildlife into your garden!

Planning

Difficulty

Moderate

Flowering time

Summer, Autumn, Spring

Harvesting

Harvest flowers when the entire flower heads and bracts turn blue.

Propagation

Seed

Propagate seeds in containers in a cold frame as soon as ripe and mature.

Division

Propagate by division during spring, although they may be slow to re-establish.

Cuttings

Insert root cuttings in late winter directly in the soil.

Special features

Attracts useful insects

Butterflies and beetles love the flowers.

Indoor plant

Grows well in pots, beds and containers in well-drained sandy soil under direct light.

Drought resistant

The fleshy roots help the plant to be drought tolerance.

Pot plant

Grows well in pots, beds and containers in well-drained sandy soil.

Attracts birds

Seed-eating songbirds.

Attracts bees

Attractive flowers

Special features

Origin

Central and Southeastern Europe and Central Asia.

Natural climate

Temperate to Cold

Environment

Light

Full Sun

Soil moisture

Dry

Soil type

Chalk, Loam, Sand

Soil PH preference

Acid, Alkaline, Neutral

Frost hardiness

Hardy

Uses

Medicinal

The plant is diuretic. It is also used in the treatment of whooping cough.

Edible

The roots are used for medicinal purposes. Taste is sweetish and mucilaginous, but the root has no odour.

Personality

Family

Apiaceae

Flower colour

Blue

Scent

None

Problems

Root rot (needs dry or well-draining soils). Leaf spot diseases. Aphids, slugs and snails.

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