// SPECIES PROFILE · ANNUAL · NATIVE

Erect knotweed

Polygonum erectum

Erect knotweed (Polygonum erectum) is a annual in the — family. Native range includes AR, KS, MO, OK. Hardy in zones 2a–11a. Mature size 1"–30". Blooms Jul–Oct.

// QUICK FACTS

Family: —
Group: annual
Native range: Native to 42 U.S. states, including AL, AR, CA, CT, DC, DE…
USDA hardiness: Zones 2a–11a
Mature size: 1"–30"
Sun: —
Water: —
Bloom: Jul–Oct
Wildlife value: Pollinator and wildlife support
Ecological role: native species profile

Erect knotweed (Polygonum erectum) — *Polygonum erectum* — Erect knotweed. Photo by Cbaile19 via Wikimedia Commons (CC0).

Field Notes

[ growing · ecology · siting · care ]

Erect knotweed (Polygonum erectum) is a annual in the — family. Native range includes AR, KS, MO, OK. Hardy in zones 2a–11a. Mature size 1"–30". Blooms Jul–Oct.

Why it's on this list: native species profile. Native-range data from the Lady Bird Johnson Wildflower Center (NPIN), cross-checked against iNaturalist observations. Part of Rooted Revival's regional native plant catalog — true natives for Oklahoma, Arkansas, Missouri and Kansas.

Companion Planting

[ guild · polyculture · cross-layer pairings ]

In the same native range, erect knotweed pairs naturally with: Common Sunflower (Helianthus annuus), Swamp verbena (Verbena hastata), Annual ragweed (Ambrosia artemisiifolia var. artemisiifolia), Two-headed water-starwort (Callitriche heterophylla).