Yes, it requires consistently wet or boggy soil to thrive.

Can I grow it in a pot?

It grows well in a container if the pot is kept sitting in a tray of water.

Plant guide

Common cottongrass.

Eriophorum angustifolium

Pronounced eh-ree-OH-for-um an-gus-ti-FO-lee-um

Also known as Bog-cotton, Common Cottongrass, Common cottonsedge, Cotton Grass, common cotton-grass

Common Cottongrass — Photo by Rostyslav Yurechko (CC BY) via iNaturalist

This charming plant is a wetland perennial known for its fluffy white seed heads that look like cotton puffs. It thrives in boggy, acidic soils and adds a soft texture to water gardens. You will love how it sways in the breeze near a pond edge.

At a glance

Care level: Moderate
Plant type: Sedge
Light: Full sun
Indoor light: Direct sun
Water: Every 1 to 2 days
Mature size: 24 inches
Growth rate: Medium
Hardiness: USDA 3 to 8
Bloom time: Late spring to early summer

Care

Keep the soil consistently saturated or submerged in shallow water to mimic its natural bog habitat. Watch for yellowing leaves which often signal the soil is drying out too much. Ensure it gets plenty of sun to encourage those signature fluffy heads.

Watering: The soil must remain constantly wet or submerged at all times.
Feeding: Use a light aquatic plant fertilizer during the active growing season.
Pruning: Trim back dead foliage in late winter or early spring.
Repotting: Divide the clumps every couple of years to keep the plant vigorous.
Soil: Peaty or boggy soil
Soil pH: Acidic
Temperature: -35 to 25°C
Humidity: 70 to 100%

Safety

People: There is no known toxicity for humans, but it is not a food source.
Children: The plant is generally safe, though the sharp leaf edges can scratch small hands.
Contact allergens: The leaves have sharp, grass-like edges that can cause minor skin abrasions.
Airborne allergens: The wind-dispersed seeds and pollen may cause mild irritation for those with severe grass allergies.
Edibility: This plant is not considered edible and should be avoided for consumption.

How to identify it

White cottony seed heads
Slender grass like leaves
Grows in dense clumps
Triangular stems in cross section

Height: 0.3 to 0.6m
Spread: 0.2 to 0.4m
Leaves: green, deciduous
Flowers: white, 2 to 5cm
Fruit: brown, Late summer

Problems to watch for

Root rot · Rarely a problem in its natural bog conditions, but stagnant, foul water in a container without water exchange can occasionally cause rot, so keep the water fresh and clean.

By symptom

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Growing it

Propagation: division, seed
When to plant: spring, autumn

Group this sedge with other moisture-loving plants to maintain a consistent bog microclimate.

Grows well with

Bogbean · They share similar moisture requirements in boggy environments.
Marsh Marigold · These plants provide a lovely color contrast in wet garden settings.

Similar species

Hare's-tail cottongrass · It has a similar appearance but features a single, rounded flower head.

Science

Family: Cyperaceae
Genus: Eriophorum
Order: Poales
Class: Liliopsida
Native range: Northern Hemisphere, including North America, Europe, and Asia.
Conservation: It is widespread and secure in its native range, requiring no special protection.

It survives in nutrient-poor, acidic wetlands by forming dense mats that stabilize boggy substrates.

Value to wildlife: nectar source, nesting material
Pollinators: bees, butterflies
Uses: bog garden accent, wetland restoration, dried floral arrangements

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 1/9
Soil reaction: 2/9
Light: 8/9
Temperature: 3/9
Moisture: 9/9
Nutrients: 2/9

Taxonomy resolved against GBIF.

Questions people ask

Does it need a pond?: Yes, it requires consistently wet or boggy soil to thrive.
Can I grow it in a pot?: It grows well in a container if the pot is kept sitting in a tray of water.

Where the name comes from

The genus name Eriophorum comes from Greek words meaning wool-bearing, while the species name angustifolium refers to its narrow leaves.

Good to know

Commonly known as common cottongrass, it is not a true grass but a sedge.
It thrives in acidic, waterlogged soils where many other plants struggle.
The white tufts were historically used to stuff pillows and cushions.

Keep your common cottongrass growing

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This guide was generated with AI on October 19, 2026 and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.