How do I get rid of it?

You must dig out every single piece of the white rhizome, as even a tiny fragment left behind will regrow.

No, do not put it in a standard compost pile because the rhizomes will likely survive and spread when you use the compost.

Plant guide

Quackgrass.

Elymus repens

Pronounced EL-ih-mus REE-penz

Also known as Common Couch, Couch, Couch Wheat Grass, Dog Grass, English Couch Grass, Quack Grass, Quackgrass, Quitch

Quackgrass is a hardy, perennial grass that spreads through aggressive underground stems called rhizomes. It is often considered a persistent weed in gardens and agricultural fields. You will find it thrives in almost any soil condition.

At a glance

Care level: Easy
Plant type: Perennial grass
Light: Full sun to partial shade
Indoor light: Direct sun
Water: Every 7 to 14 days
Mature size: 3 feet
Growth rate: Fast
Hardiness: USDA 3 to 9
Bloom time: Mid to late summer

Care

This plant is highly invasive and difficult to remove once established. Focus on manual removal of all rhizome fragments to prevent regrowth. Watch for new shoots appearing in garden beds or lawns.

Watering: It is quite drought tolerant once established.
Feeding: This plant does not require supplemental fertilizer.
Pruning: Mow or cut back frequently to prevent seed head formation.
Repotting: It is not recommended to keep this plant in a container due to its invasive nature.
Soil: Well-draining soil
Soil pH: 6.0 to 8.0
Temperature: -30 to 35°C
Humidity: 40 to 80%
Drought tolerance: High
Lifespan: Perennial, indefinite growth through rhizomes.
Deer and rabbits: High

Safety

People: This plant is not considered toxic to humans.
Children: The sharp edges of the leaves can cause paper-like cuts on children's skin if handled roughly.
Contact allergens: The leaf blades have fine, sharp serrations that can cause minor skin abrasions.
Airborne allergens: The pollen produced in summer can be a significant trigger for seasonal hay fever.
Edibility: While the rhizomes are technically edible, they are extremely tough and fibrous, making them poor food sources.

How to identify it

Long, creeping white rhizomes
Flat, dull green leaf blades
Small, spike-like flower heads
Auricles clasping the stem base

Height: 0.3 to 1.2m
Spread: 0.3 to 9.99m
Leaves: green, blue-green, deciduous
Flowers: green, straw, 5 to 15cm

Problems to watch for

Rust · Fungal infection causing orange or brown pustules on the leaves.

By symptom

Plant problems by symptom

Check your quackgrass from a photo

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Growing it

Propagation: division, seed
When to plant: spring, autumn
Overwintering: The foliage will die back to the ground in winter. No special care is needed as the underground rhizomes are fully hardy.
In containers: It is not recommended for containers, as it will quickly become root-bound and attempt to escape through drainage holes.

Rhizome Division

1. Dig up a section of the soil containing the white rhizomes.
2. Cut the rhizomes into segments that each have at least one node.
3. Replant the segments in the desired location.

It is best to avoid planting this in any garden setting, as it is a highly invasive species that dominates other plants.

Similar species

Smooth Brome · It shares a similar aggressive spreading habit and grassy appearance.

Science

Family: Poaceae
Genus: Elymus
Order: Poales
Class: Liliopsida
Native range: Europe, Asia, and parts of North Africa.
Conservation: This plant is considered a widespread invasive weed in many parts of the world and is not of conservation concern.

It thrives in disturbed soils and spreads rapidly through an extensive underground network of rhizomes.

Value to wildlife: larval host plant, nesting material
Pollinators: bees, butterflies
Uses: soil stabilization, erosion control, forage

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 3/9
Soil reaction: 6/9
Light: 7/9
Temperature: 5/9
Moisture: 5/9
Nutrients: 6/9

Taxonomy resolved against GBIF.

Questions people ask

How do I get rid of it?: You must dig out every single piece of the white rhizome, as even a tiny fragment left behind will regrow.
Can I compost it?: No, do not put it in a standard compost pile because the rhizomes will likely survive and spread when you use the compost.

Where the name comes from

The name repens is Latin for creeping, which perfectly describes its aggressive growth habit.

Good to know

It is commonly known as quackgrass.
The rhizomes can grow up to 3 meters in a single season.
It is extremely difficult to eradicate once established in a garden bed.

Keep your quackgrass 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.