How big does Glaucous sedge grow?

About 30 cm × 45 cm after ten years (height × width). Its ultimate size is 15–45 cm × 30–45 cm.

What soil does Glaucous sedge grow in?

It tolerates these soils: average garden soil, clay, sandy, calcareous.

Is Glaucous sedge hardy?

Hardy down to -34 °C (USDA zone 4, RHS H7). It gets through winter in every part of the country.

When does Glaucous sedge flower?

Flowering: April–July, green.

How much water does Glaucous sedge need?

Water need: medium. Drought tolerance: medium.

Glaucous sedge

Carex flacca

Glaucous sedge (Carex flacca) is an ornamental grass that reaches 30 cm × 45 cm after ten years. Light: full sun, part shade, shade. Hardy down to -34 °C. Drought tolerance: medium.

Illustration of Glaucous sedge — An illustration of the typical shape of the mature plant, not a photo.

What it's good for, and what it isn't

A low evergreen sedge with blue-green leaves that are glaucous beneath, slowly knitting into a dense carpet by short rhizomes. It is very adaptable: it grows in sun or shade, in moist or fairly dry, limy or clay soil, and puts up with occasional foot traffic, so it makes a good ground cover under trees, on banks or as a lawn substitute for small patches. Expect it to creep in among its neighbours over time and cut the edges back with a spade now and then.

Watch out for

No serious pests or diseases. In Central Europe the foliage browns in hard winters: comb it out or cut it back in late winter so the new growth comes through clean. In full sun and prolonged drought the leaf tips dry out, so water then or plant it in part shade from the start. It spreads by rhizomes and can gradually swamp small, weak-growing neighbours.

Key facts

Light: Full sun, Part shade, Shade
Water need: Medium
Care: Low
Size after 10 years: 30 cm × 45 cm
Hardiness: down to -34 °C
Foliage: Evergreen
Flowering: J F M A M J J A S O N D April–July, green

Group	Ornamental grass
Light	Full sun, Part shade, Shade
Size after 10 years	30 cm × 45 cm
Ultimate size	15–45 cm × 30–45 cm
Hardiness	down to -34 °C (USDA 4, RHS H7)
Soil	Average garden soil, Clay, Sandy, Calcareous
Foliage	Evergreen
Flowering	April–July, green
Water need	Medium
Drought tolerance	Medium
Maintenance	Low
Root aggressiveness	Low
Suckering	no data
Spreading	Medium
Distance from buildings	no data
Distance from paving	no data
Litter	not typical
Planting distance	30 cm
For dogs	no data
For cats	no data
For children	no data
Typical price	no data

Toxicity data is for information only. If your pet or child has eaten a plant, contact a vet or a doctor.

Frequently asked questions

Data updated: October 8, 2026 · How our data is made

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