No, it is an annual that completes its life cycle in one season.

Does it need a lot of water?

Yes, it prefers consistently moist to damp soil conditions.

Plant guide

Marsh cudweed.

Gnaphalium uliginosum

Pronounced naf-AY-lee-um yoo-li-ji-NO-sum

Also known as Cudweed, Low Cudweed, Marsh Cudweed, Mouse-ear

The marsh cudweed is a charming little annual that loves damp, disturbed ground. It is quite common in meadows and along paths where the soil stays moist. You will find it is a modest plant that adds a nice touch of texture to a wild garden.

At a glance

Care level: Easy
Plant type: Annual herb
Light: Full sun
Indoor light: Direct sun
Water: Every 2 to 4 days
Mature size: 2 to 8 inches
Growth rate: Medium
Hardiness: USDA 3 to 9
Bloom time: Mid to late summer

Care

Keep the soil consistently moist to mimic its natural wetland habitat. Watch for wilting, which is a clear sign the plant needs more water. It thrives best when it has plenty of space to spread out in full sun.

Watering: Keep the soil damp at all times, as this plant does not tolerate drying out.
Feeding: A light application of balanced liquid fertilizer once during the growing season is plenty.
Pruning: Trim back any dead or straggly stems to encourage a bushier habit.
Repotting: Since it is an annual, you will typically start fresh from seed each year.
Soil: Moist, sandy, or loamy soil
Soil pH: Neutral to slightly acidic
Temperature: -20 to 30°C
Humidity: 40 to 80%

Safety

People: There are no reports of significant toxicity, but it is not intended for human consumption.
Children: Keep away from small children as the plant is not food and the fine hairs could be an irritant if handled.
Contact allergens: The fine, woolly hairs on the leaves may cause mild skin irritation in sensitive individuals.
Airborne allergens: The tiny, wind-dispersed pollen may trigger mild hay fever symptoms in some people.
Edibility: This plant is not considered edible and should not be consumed.

How to identify it

Small, woolly, lance shaped leaves
Tiny, yellowish flower heads
Branching stems covered in white hairs
Grows in low, spreading clusters

Height: 0.05 to 0.2m
Spread: 0.1 to 0.3m
Leaves: gray-green, deciduous
Flowers: yellow, white, 0.2 to 0.5cm

Problems to watch for

Powdery mildew · Appears as a white dusty coating on leaves during periods of high humidity.

By symptom

Plant problems by symptom

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Growing it

Propagation: seed
When to plant: spring

Group this plant with others that enjoy wet feet to create a thriving boggy corner in your garden.

Grows well with

Soft Rush · They both thrive in the same damp, boggy soil conditions.
Creeping Jenny · It makes a lovely low-growing partner for moist garden edges.

Similar species

Purple Cudweed · It shares a similar woolly appearance and growth habit.

Science

Family: Asteraceae
Genus: Gnaphalium
Order: Asterales
Class: Magnoliopsida
Native range: Europe and parts of Asia and North America.
Conservation: It is a common weed in many areas and is not of conservation concern.

It is a pioneer species that quickly occupies bare, wet, or disturbed ground.

Value to wildlife: nectar source
Pollinators: bees, butterflies
Uses: ground cover, wildlife garden filler

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 1/9
Soil reaction: 5/9
Light: 7/9
Temperature: 5/9
Moisture: 8/9
Nutrients: 4/9

Taxonomy resolved against GBIF.

Questions people ask

Is it a perennial?: No, it is an annual that completes its life cycle in one season.
Does it need a lot of water?: Yes, it prefers consistently moist to damp soil conditions.

Where the name comes from

The name Gnaphalium comes from the Greek word for wool, referring to the plant's fuzzy texture, while uliginosum means growing in swamps or marshes.

Good to know

It is commonly known as marsh cudweed.
The plant is covered in a dense, woolly mat of hairs that helps it retain moisture.
It thrives in compacted soil, often appearing in muddy paths.

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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.