It can be aggressive in small gardens due to its spreading roots.

Does it need full sun?

Yes, it prefers full sun to bloom well.

Plant guide

Fireweed.

Chamaenerion angustifolium

Pronounced kam-uh-NEER-ee-on an-gus-ti-FO-lee-um

Also known as Fireweed, French-willow, Great Willowherb, Rosebay Willowherb, Willowherb

Fireweed is a hardy perennial known for its vibrant spikes of pink to purple flowers. It often colonizes areas quickly after disturbances like wildfires. You will love how it brings a splash of color to meadows and forest edges.

Another photo of Fireweed — Photo by Marilynn Miller (CC BY) via iNaturalist

At a glance

Care level: Easy
Plant type: Perennial herb
Light: Full sun
Indoor light: Direct sun
Water: Every 3 to 7 days
Mature size: 3 to 6 feet
Growth rate: Fast
Hardiness: USDA 2 to 8
Bloom time: Mid to late summer

Care

Plant this in a spot with plenty of sun and well draining soil. Keep an eye on its spread since it can be quite aggressive in the garden. Watch for wilting if the soil dries out too much during the heat of summer.

Watering: Keep the soil consistently moist but not waterlogged.
Feeding: Apply a balanced fertilizer once during the spring growth phase.
Pruning: Cut back the dead stalks to the ground in late autumn or early spring.
Repotting: Repot only if the plant becomes root bound in its container.
Soil: Well draining sandy or rocky soil
Soil pH: 5.5 to 7.0
Temperature: -35 to 30°C
Humidity: 40 to 70%
Drought tolerance: Moderate
Lifespan: Perennial, typically 5 to 10 years.
Fragrance: Light
Deer and rabbits: Moderate

Signs it needs repotting

Roots growing out of the drainage holes.
Stunted growth during the active season.

Safety

People: The plant is generally considered non toxic to humans.
Children: The fluffy seeds are a choking hazard if ingested in large amounts.
Contact allergens: The sap may cause mild skin irritation in sensitive individuals.
Airborne allergens: The fine, hair like seeds can be a minor irritant if inhaled in large quantities.
Edibility: Young shoots are edible, but mature leaves can become tough and bitter.

How to identify it

Tall spikes of pink flowers
Lance shaped narrow leaves
Reddish stems
Seed pods split open to release fluff

Height: 0.6 to 1.5m
Spread: 0.3 to 0.6m
Leaves: green, deciduous
Flowers: pink, magenta, 2 to 4cm
Fruit: brown, Autumn

Problems to watch for

AphidsCommon
RustCommon
CaterpillarsUncommon
Leaf SpotUncommon
Powdery MildewUncommon
Root RotRare

By symptom

Plant problems by symptom

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Growing it

Propagation: division, seed, cuttings
When to plant: spring, autumn
Overwintering: Cut the stems back to the ground after the foliage dies in late autumn.
In containers: It is not ideal for containers because of its aggressive rhizomatous growth.

Division

1. Dig up the clump in early spring.
2. Separate the rhizomes with a sharp spade.
3. Replant immediately in moist soil.

Plant in large drifts to create a strong visual impact and support local bee populations.

Grows well with

Goldenrod · They share similar light and moisture requirements.
Aster · They provide a late season nectar source for pollinators.

Similar species

Purple Loosestrife · It has a similar flower spike shape but is considered invasive.

Science

Family: Onagraceae
Genus: Chamaenerion
Order: Myrtales
Class: Magnoliopsida
Native range: Northern Hemisphere temperate regions.
Conservation: This species is widespread and not of conservation concern.

It is a pioneer species that thrives in disturbed soil and open, sunny areas.

Value to wildlife: nectar source, larval host plant
Pollinators: bees, butterflies, moths
Uses: pollinator garden, wildflower meadow, pioneer species, culinary shoots

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 2/9
Soil reaction: 5/9
Light: 8/9
Temperature: 4/9
Moisture: 5/9
Nutrients: 4/9

Taxonomy resolved against GBIF.

Questions people ask

Is it invasive?: It can be aggressive in small gardens due to its spreading roots.
Does it need full sun?: Yes, it prefers full sun to bloom well.

Where the name comes from

The name angustifolium refers to its narrow leaves, while fireweed describes its tendency to appear after fires.

Good to know

It is also known as fireweed.
The leaves are sometimes used to make a fermented tea.
It spreads rapidly through underground rhizomes.
The flowers open from the bottom of the spike to the top.

Keep your fireweed growing

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This guide was generated with AI on September 26, 2026 and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.