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Broadleaf Knotweed

Polygonum minimum

Last reviewed: June 2026

Broadleaf Knotweed (Polygonum minimum)
Photo: (c) Alison Northup, some rights reserved (CC BY), uploaded by Alison Northup

Light

full sun

Water

low

Size

2"–8" H × 4"–12" W

Bloom

Jun, Jul, Aug, Sep

Native to

CA, CO, ID, MT and 5 more states

Pollinators

bees, beetles

Browse plants for this ecoregion

Broadleaf knotweed is a low-growing annual that forms small mats with tiny leaves and inconspicuous flowers. This diminutive native plant thrives in sunny, dry conditions and completes its entire life cycle in one growing season.

In an HOA neighborhood

Broadleaf 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.

  • Extremely weedy appearance
  • Dies back completely as annual
  • Too informal for maintained landscapes

Wildlife value

The small flowers attract bees and beetles during the summer months. Seeds may provide food for small birds and ground-dwelling wildlife.

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 Broadleaf Knotweed fit your yard? Open it in Pollinator Patch to check it against your sun, soil, and HOA-conscious filters.