What growing conditions does American willowherb prefer?

Epilobium ciliatum grows best in part shade with medium, fairly consistent moisture, and it is commonly found along streambanks, ditches, and wet meadow edges.

When does Epilobium ciliatum bloom?

It typically blooms from June through September, producing small pink to white flowers in loose clusters.

What pollinators visit American willowherb flowers?

Bees and butterflies are commonly observed visiting the flowers of Epilobium ciliatum for nectar and pollen.

Is American willowherb a good choice for a home garden?

It can work well in rain gardens, moist borders, and naturalistic plantings where soil stays evenly damp through the growing season.

Is American Willowherb HOA-friendly?

American Willowherb takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.

American Willowherb

Name: Pollinator Patch
Author: Pollinator Patch

Epilobium ciliatum

Last reviewed: September 2026

American willowherb (Epilobium ciliatum) is a forb that blooms June through September, favoring part shade and medium to consistently moist soil along streambanks, ditches, and wet meadows.

Toxicity unknown

American Willowherb (Epilobium ciliatum) is not listed by the ASPCA Animal Poison Control Center (opens in new tab) or the other sources we check, so we have no verdict for it either way. Absence from those lists is not a clearance. If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.

Light

part shade

Water

medium

Size

12"–48" H × 6"–24" W

Bloom

Jun, Jul, Aug, Sep

Native to

AZ, CA, CO, CT and 38 more states

Pollinators

bees, butterflies

Before you buy

Your city may pay you to plant this

Cities and water utilities offer rebates for replacing lawn with native and water-wise plants. We track 452 programs across 44 states, each with a link to the provider and the date we last checked it.

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Browse plants for this ecoregion

Coast Range Puget Lowland Marine West Coast Forest Northwestern Forested Mountains Sierra Nevada Central California Foothills and Coastal Mountains Central California Valley Southern California Mountains North American Deserts Central Basin and Range Mojave Basin and Range Southern Rockies Arizona/New Mexico Mountains Chihuahuan Deserts High Plains Southwestern Tablelands Central Great Plains Northwestern Glaciated Plains Northwestern Great Plains Great Plains Northern Glaciated Plains Western Corn Belt Plains Northern Forests Northern Lakes and Forests North Central Hardwood Forests Driftless Area Southeastern Wisconsin Till Plains Central Corn Belt Plains Eastern Corn Belt Plains Southern Michigan/Northern Indiana Drift Plains Huron/Erie Lake Plains Northeastern Highlands Northeastern Coastal Zone Northern Allegheny Plateau Erie Drift Plain Middle Atlantic Coastal Plain Northern Piedmont Ridge and Valley Central Appalachians Western Allegheny Plateau Madrean Archipelago Sonoran Basin and Range Acadian Plains and Hills Eastern Great Lakes Lowlands Atlantic Coastal Pine Barrens Southern California/Northern Baja Coast

American willowherb is a native perennial with narrow leaves and small pink to purple flowers that bloom from summer into fall. It forms loose colonies through underground runners and adapts well to partially shaded, moist areas where many other natives struggle.

Growing American Willowherb

Grow American Willowherb in part shade and medium water. Mature plants reach 12 to 48 inches tall and spread 6 to 24 inches wide. Expect moderate maintenance to keep it looking intentional in a front yard.

In an HOA neighborhood

American Willowherb takes more care to keep looking intentional in a front yard. Maintenance level: moderate. Consider it for backyard or mid-zone beds rather than the street edge.

Works well in: backyard only.

Spreads aggressively and can look weedy
May be perceived as too wild or uncontrolled
Dies back completely in winter leaving bare patches

Wildlife value

The flowers attract various bees and butterflies throughout the long blooming season. Seeds provide food for birds, and the plant serves as a host for some moth caterpillars.

Common questions

What growing conditions does American willowherb prefer?: Epilobium ciliatum grows best in part shade with medium, fairly consistent moisture, and it is commonly found along streambanks, ditches, and wet meadow edges.
When does Epilobium ciliatum bloom?: It typically blooms from June through September, producing small pink to white flowers in loose clusters.
What pollinators visit American willowherb flowers?: Bees and butterflies are commonly observed visiting the flowers of Epilobium ciliatum for nectar and pollen.
Is American willowherb a good choice for a home garden?: It can work well in rain gardens, moist borders, and naturalistic plantings where soil stays evenly damp through the growing season.
Is American Willowherb HOA-friendly?: American Willowherb takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.

These answers were drafted with an AI model from this plant's data. Verify care details with a local expert.

Native range data from vouchered herbarium specimen records and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.

If something looks wrong

Common plant problems, and what to check first

These come up on almost any plant. Each guide lists the likely causes in the order they are worth ruling out, with one thing to check before you act on any of them, and links to the source it came from.

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