California-bur
Xanthium strumarium
Last reviewed: July 2026
Light
full sun
Water
medium
Size
12"–48" H × 12"–36" W
Bloom
Jul, Aug, Sep
Native to
AL, AR, CA, CO and 40 more states
Pollinators
bees, beetles
Browse plants for this ecoregion
A sturdy annual forb that grows 1-4 feet tall with broad leaves and small greenish flowers from July through September. This plant produces distinctive spiny seed pods that can stick to clothing and animal fur. It thrives in full sun with average moisture and establishes quickly from seed.
In an HOA neighborhood
California-bur takes more care to keep looking intentional in a front yard. Maintenance level: high. Consider it for backyard or mid-zone beds rather than the street edge.
- Classified as noxious weed
- Produces painful spiny burrs
- Looks extremely weedy and unkempt
Wildlife value
The summer flowers attract bees and beetles for pollination. The seeds provide food for birds and small mammals.
Common questions
- How much sun does California-bur need?
- California-bur grows best in full sun conditions.
- When does California-bur bloom?
- California-bur blooms in July, August, and September.
- Where is California-bur native?
- California-bur (Xanthium strumarium) is native to AL, AR, CA, CO and 40 more states, per the USDA PLANTS Database and regional native plant society lists.
- What pollinators does California-bur attract?
- California-bur draws bees and beetles.
- Is California-bur HOA-friendly?
- California-bur 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 the USDA PLANTS Database and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
Ready to grow California-bur? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.
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