Oval-leaf Knotweed
Polygonum arenastrum
Last reviewed: June 2026
Light
full sun
Water
low
Size
4"–12" H × 6"–18" W
Bloom
Jun, Jul, Aug, Sep
Native to
WY
Pollinators
bees, beetles
Browse plants for this ecoregion
Oval-leaf knotweed is a low-growing annual that forms spreading mats with small oval leaves and tiny clustered flowers. This hardy plant thrives in poor soils and difficult conditions where other plants struggle. It blooms from June through September with small white or pinkish flowers.
In an HOA neighborhood
Oval-leaf 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.
- Spreads aggressively and can look weedy
- May be considered invasive or undesirable by neighbors
- Low, matting growth habit appears unkempt in formal settings
Wildlife value
The long blooming period provides nectar for bees and beetles throughout the growing season. Its seeds may also provide food for small birds.
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.
Does Oval-leaf Knotweed fit your yard? Open it in Pollinator Patch to check it against your sun, soil, and HOA-conscious filters.