Western Ragweed
Ambrosia psilostachya
Also listed as Ambrosia coronopifolia, Ambrosia rugelii
Also known as Perennial Ragweed, Cuman Ragweed, Roman Wormwood
Climate Match for your location
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Western ragweed is a native perennial wildflower with a tall, branching form that produces dense spikes of small, wind-pollinated flowers in late summer and fall. It thrives in dry, open areas and is commonly found in prairies and disturbed areas across the western and central United States.
Why grow it
Western ragweed establishes readily in marginal soils where many ornamental perennials struggle, making it useful for erosion control and habitat restoration in arid and semi-arid regions. Its late-season flowering provides a nectar source when other wildflowers have declined, supporting pollinators and beneficial insects during a critical period. Compared to cultivated ornamentals requiring irrigation and amendment, it demands minimal input once established in appropriate conditions.
Watch out for
Western ragweed can spread vigorously in disturbed soils, so containment may be necessary in managed garden settings. The plant's prolific seed production means deadheading or removal before seed set is important if you wish to prevent volunteer plants in adjacent areas. While it establishes readily in poor soil, consistent moisture during establishment helps ensure stronger root development.
Overview
- Form
- Growth Rate
- Size
- Dormancy
- Family
- Asteraceae
Native to the United States
Native Range
Western and central North America
Native to: Alabama, Arkansas, Arizona, California, Colorado, Connecticut, Florida, Georgia, Iowa, Idaho, Illinois, Indiana, Kansas, Louisiana, Massachusetts, Maine, Michigan, Minnesota, Missouri, Mississippi, Montana, North Carolina, North Dakota, Nebraska, New Hampshire, New Mexico, Nevada, New York, Ohio, Oklahoma, Oregon, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Washington, Wisconsin, Wyoming
Seasonality
Bloom Season
Season of Interest
Herb
Soft non-woody plants of the field layer.
Succession Role
Tolerances & Soil
Establishment & Care
- Establishment
- Maintenance
- Propagation
Western ragweed is a native perennial wildflower with a tall, branching form that produces dense spikes of small, wind-pollinated flowers in late summer and fall. It thrives in dry, open areas and is commonly found in prairies and disturbed areas across the western and central United States.
Climate Match for your location
See how well Western Ragweed grows in your area.
Enter your ZIP code and we'll show you how this plant fits your local climate.
Why grow it
Western ragweed establishes readily in marginal soils where many ornamental perennials struggle, making it useful for erosion control and habitat restoration in arid and semi-arid regions. Its late-season flowering provides a nectar source when other wildflowers have declined, supporting pollinators and beneficial insects during a critical period. Compared to cultivated ornamentals requiring irrigation and amendment, it demands minimal input once established in appropriate conditions.
Watch out for
Western ragweed can spread vigorously in disturbed soils, so containment may be necessary in managed garden settings. The plant's prolific seed production means deadheading or removal before seed set is important if you wish to prevent volunteer plants in adjacent areas. While it establishes readily in poor soil, consistent moisture during establishment helps ensure stronger root development.
Overview
- Form
- Growth Rate
- Size
- Dormancy
- Family
- Asteraceae
Native to the United States
Native Range
Western and central North America
Native to: Alabama, Arkansas, Arizona, California, Colorado, Connecticut, Florida, Georgia, Iowa, Idaho, Illinois, Indiana, Kansas, Louisiana, Massachusetts, Maine, Michigan, Minnesota, Missouri, Mississippi, Montana, North Carolina, North Dakota, Nebraska, New Hampshire, New Mexico, Nevada, New York, Ohio, Oklahoma, Oregon, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Washington, Wisconsin, Wyoming
Seasonality
Bloom Season
Season of Interest
Herb
Soft non-woody plants of the field layer.
Succession Role
Tolerances & Soil
Establishment & Care
- Establishment
- Maintenance
- Propagation
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