Douglas's Knotweed
Polygonum douglasii
Last reviewed: June 2026
Light
full sun
Water
low
Size
4"–16" H × 2"–8" W
Bloom
Jun, Jul, Aug
Native to
AZ, CA, CO, IA and 16 more states
Pollinators
bees, beetles
Browse plants for this ecoregion
Douglas's knotweed is a low-growing annual wildflower that forms small mats close to the ground. It produces tiny white or pink flowers during summer months and thrives in sunny, dry conditions with minimal water requirements.
In an HOA neighborhood
Douglas's Knotweed 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.
- Very small stature may appear weedy
- Annual lifecycle creates gaps when plant dies
- Common name includes 'weed' which raises HOA concerns
Wildlife value
This plant provides nectar for native bees and serves as a food source for beetles during its summer blooming period.
Common questions
- How much sun does Douglas's Knotweed need?
- Douglas's Knotweed grows best in full sun conditions.
- When does Douglas's Knotweed bloom?
- Douglas's Knotweed blooms in June, July, and August.
- Where is Douglas's Knotweed native?
- Douglas's Knotweed (Polygonum douglasii) is native to AZ, CA, CO, IA and 16 more states, per the USDA PLANTS Database and regional native plant society lists.
- What pollinators does Douglas's Knotweed attract?
- Douglas's Knotweed draws bees and beetles.
- Is Douglas's Knotweed HOA-friendly?
- Douglas's Knotweed 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 Douglas's Knotweed? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.
Not sure where to start? Take the 2-minute yard quiz