How to Grow Eriophorum Plants in your Garden

Gardener's HQ Guide to Growing Cotton grass and Cotton Sedge

Members of the Eriophorum plant genus are oriental grasses that can reach from 30 to 90 cm in height.

They are hardy perennials that flower in the Summer.

They have long lasting flowers of cottony white; hence the common name for Eriophorum of Cotton grass.

They like moist conditions so are great to grow next to water features or in boggy parts of the garden.

Eriophorum spissum
Eriophorum spissum - Tussock cottongrass by peupleloup.

Cottongrass by Leo-setä.

Eriophorum Growing and Care Guide

Common Names: Cottongrass, Cotton Sedge, Cotton Grass.
Life Cycle: Hardy perennial
Height: 12 to 36 inches (30 to 90 cm).
Native: Northern America, Europe, Asia.

Growing Region: Zones 4 to 10.
Flowers: Summer.
Flower Details: White. Cotton-like.
Foliage: Herbaceous. Often leaf-less.
Sow Outside: Surface. First two months of spring. Germination time: 3 weeks. Temperature: 560 to 75°F (16 to 24°C). Spacing 12 to 18 inches (30 to 45 cm).

Sow Inside: No
Requirements and care: Full sunlight or shade. Grows in moist soil or shallow water. Acidic soil. Heavy watering to maintain soil is always moist/waterlogged. Cut back heavily at the start of spring. Propagate: by dividing in the spring.

Miscellaneous: The Common Cottongrass Eriophorum augustifolium is the county flower of Greater Manchester. Some species are food plants for geese and reindeer. Used as an alternative to a diaper/nappy by Inuits.

How to Grow Cotton Grass (Eriophorum)

It is best to grow Cotton grass from seed in their final location; simply sow the seeds on the surface at about 40 cm apart.

Cotton grass likes to grow in moist acidic soil. It is best to plant Eriophorum species in the first couple of months of spring so as to flower in summer.

The Cotton grass seeds will take about three weeks to germinate once the temperature has reached about 15 degrees Centigrade.

Caring for Cottongrass and other Eriophorum plants in in the Garden

They can be grown in either sunny or shady conditions. Cotton grass is fairly easy to maintain.

It is important to keep the soil very moist, and the plant should be cut back at the beginning of spring.

I hope that you enjoyed this guide on how to grow Eriophorum plants. Updated September 2020.