The Gardeners Almanac

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Eryngium

Common name: Sea Holly

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Week Numbers

Coldframe

Collecting seeds

Compost

Division

Frost

Planting out

Pricking Out

Root cuttings

Seed sowing

Overview:

Ripe seed heads ready for  harvesting

Seed Heads

 Clump of Sea holly

Eryngium-Joss Eijking

Sea Hollies are ideal for using as cut, or dried flowers.

The blue or white umbels and bracts form from midsummer onwards.


Select blooms for drying when the flowers are in full bloom.

Tie them into bunches and hang them upside down in a dark and well-ventilated place until suitably dried.


They are fully hardy, but will benefit from protection during cold wet winter conditions.

They require free draining soil and a sunny aspect to be seen at their best.


As their name suggests, they can grow in nutritionally poor soil (shingle beaches) and in salty conditions.

When grown in humus rich soil, the roots will not grow quite as large or fleshy.

They will tolerate drought conditions once they become established.

They can grow to 60cm-90cm (2ft-3ft) high.


Cultivation:

Week 8:

If weather and ground conditions are suitable take root cuttings.

Place cuttings in a 50-50 mix of compost and sharp sand and grow on in a cold frame.

Pot on when of a suitable size to handle, and grow on in a cold frame until till planting out time.


Week 10:

Sow seed on the surface of trays filled with seed compost and place in a cold frame until germinated.

Alternatively, collect ripe seeds after flowering and sow immediately and treat as spring sown seed.

Seed germination can be a bit erratic with germination times ranging from a week to six months.

Prick out the seedlings into 70mm (3”) pots of potting compost and grow on in a cold frame until planting out time.


Week 14:

Divide established plants if weather conditions allow, and re- plant immediately.

Choose the younger parts of the root system.

Sea Holly has a long tap root, which can make transplanting somewhat difficult.


Week 40:

Plant out 600mm (24") apart in any dry, well-drained soil in full sun, or wait until spring and plant out after the last of late frosts.