Eriophorum angustifolium - Common Cottongrass, Native Pond Marginal Pl

Eriophorum angustifolium, known as common cottongrass or bog cotton, is a UK native sedge of bogs and boggy moorland. Its small flowers in spring are followed by white, cotton-wool seed heads, which are most noticeable in summer. It is a sedge, not a true grass.

Common cottongrass at a glance

Botanical name	Eriophorum angustifolium
Common name	Common cottongrass, bog cotton
Plant type	Evergreen sedge; spreads by rhizomes
Height and spread	About 30 cm tall (up to 50 cm), spreading 1–1.5 m
Flowers	Small and inconspicuous, April to June, followed by white cottony seed heads
Position	Full sun
Soil	Wet, poorly drained, acid soil
Pond depth	0–5 cm of water over the crown
Hardiness	RHS H7 – very hardy (below -20°C)
Native to	UK and Ireland (native wild plant)

Where to plant common cottongrass

Acid bog gardens
The wet edge of a wildlife pond, with up to 5 cm of water over the crown
A sunny, open spot

What soil does it need?

Wet, acid soil. It may struggle in alkaline or nutrient-rich ponds, so it is best in acid conditions.

Does it spread?

Yes. It spreads by rhizomes and covers ground better than the tufted Eriophorum vaginatum. The RHS gives a spread of 1–1.5 m.

Is it legal to grow?

Yes. It is a native plant and is not on any restricted list. Buy nursery-grown plants: digging up wild plants without the landowner's permission is an offence.

Which size should I buy?

Bare-root plants (7 cm, 9 cm, 1 litre and 3 litre) arrive without a pot or compost and are the most economical way to plant a group. Potted plants (9 cm, 1 litre and 3 litre) arrive growing in our peat-free compost and give a faster display. Packs of 3 come in 7 cm, 9 cm, 1 litre and 3 litre bare-root sizes and cost less per plant. The 2x Pot & Compost option is two plants supplied with pots and compost.