How much sun does Horseweed need?

Horseweed grows best in full sun conditions.

When does Horseweed bloom?

Horseweed blooms in July, August, September, and October.

Where is Horseweed native?

Horseweed (Erigeron canadensis) is native to AL, AR, AZ, CA and 43 more states, per vouchered herbarium specimen records and regional native plant society lists.

What pollinators does Horseweed attract?

Horseweed draws bees, beetles, and flies.

Is Horseweed HOA-friendly?

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

Horseweed

Name: Pollinator Patch
Author: Pollinator Patch

Erigeron canadensis

Last reviewed: August 2026

Toxicity unknown

Horseweed (Erigeron canadensis) 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

full sun

Water

low

Size

12"–60" H × 6"–24" W

Bloom

Jul, Aug, Sep, Oct

Native to

AL, AR, AZ, CA and 43 more states

Pollinators

bees, beetles, flies

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 445 programs across 44 states, each with a link to the provider and the date we last checked it.

Find rebates in your area

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 Great Plains Cross Timbers Edwards Plateau Southern Texas Plains Texas Blackland Prairies East Central Texas Plains Western Gulf Coastal Plain South Central Plains Eastern Temperate Forests Ozark Highlands Central Irregular Plains Northwestern Glaciated Plains Northwestern Great Plains Piedmont 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 Southeastern Plains Blue Ridge Ridge and Valley Central Appalachians Western Allegheny Plateau Interior Plateau Interior River Valleys and Hills Mississippi Alluvial Plain Mississippi Valley Loess Plains Southern Coastal Plain Southern Florida Coastal Plain Madrean Archipelago Sonoran Basin and Range Acadian Plains and Hills Eastern Great Lakes Lowlands Atlantic Coastal Pine Barrens Southern California/Northern Baja Coast

Horseweed is a tall annual wildflower that grows rapidly from spring through fall, producing small white daisy-like flowers in dense clusters. This pioneer species thrives in disturbed soils and poor conditions where other plants struggle. It self-seeds readily and can become quite abundant in suitable locations.

In an HOA neighborhood

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

Works well in: backyard only.

Often considered a weed due to weedy appearance
Self-seeds aggressively and can spread rapidly
Tall gangly growth habit looks unkempt in formal settings

Wildlife value

The abundant small flowers provide nectar for bees, beneficial flies, and beetles from mid-summer through fall. Seeds feed birds and small mammals in winter.

Common questions

How much sun does Horseweed need?: Horseweed grows best in full sun conditions.
When does Horseweed bloom?: Horseweed blooms in July, August, September, and October.
Where is Horseweed native?: Horseweed (Erigeron canadensis) is native to AL, AR, AZ, CA and 43 more states, per vouchered herbarium specimen records and regional native plant society lists.
What pollinators does Horseweed attract?: Horseweed draws bees, beetles, and flies.
Is Horseweed HOA-friendly?: Horseweed takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.

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.

Ready to grow Horseweed? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.

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