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Pleatleaf Knotweed

Polygonum tenue

Last reviewed: September 2026

Pleatleaf Knotweed (Polygonum tenue)
Photo: (c) Zihao Wang, some rights reserved (CC BY)

Toxicity unknown

Pleatleaf Knotweed (Polygonum tenue) is not listed by the ASPCA Animal Poison Control Center (opens in new tab) or the other sources we check, so we have no verdict for it either way. Absence from those lists is not a clearance. If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.

Light

part sun

Water

medium

Size

4"–16" H × 2"–8" W

Bloom

Jul, Aug, Sep

Native to

AL, AR, CT, DE and 30 more states

Pollinators

bees, beetles

Before you buy

Your city may pay you to plant this

Cities and water utilities offer rebates for replacing lawn with native and water-wise plants. We track 452 programs across 44 states, each with a link to the provider and the date we last checked it.

Find rebates in your area

Browse plants for this ecoregion

Central Great PlainsGreat PlainsCross TimbersTexas Blackland PrairiesEast Central Texas PlainsSouth Central PlainsEastern Temperate ForestsOzark HighlandsCentral Irregular PlainsPiedmontNorthern Glaciated PlainsWestern Corn Belt PlainsNorthern Lakes and ForestsNorth Central Hardwood ForestsDriftless AreaSoutheastern Wisconsin Till PlainsCentral Corn Belt PlainsEastern Corn Belt PlainsSouthern Michigan/Northern Indiana Drift PlainsHuron/Erie Lake PlainsNortheastern HighlandsNortheastern Coastal ZoneNorthern ForestsMiddle Atlantic Coastal PlainNorthern PiedmontSoutheastern PlainsBlue RidgeRidge and ValleyWestern Allegheny PlateauInterior PlateauInterior River Valleys and HillsAtlantic Coastal Pine Barrens

Pleatleaf knotweed is a small annual wildflower that grows in low, spreading clumps. It produces tiny white or pinkish flowers from July through September and thrives in partial sun with moderate moisture. This delicate plant typically reaches only 4 to 16 inches tall with a modest spread.

In an HOA neighborhood

Pleatleaf 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 small and inconspicuous appearance
  • Annual nature means gaps in coverage
  • Can appear weedy or unkempt

Wildlife value

The summer blooms provide nectar for native bees and beetles during the mid to late growing season. As a native annual, it also contributes to the local ecosystem's plant diversity.

Common questions

How much sun does Pleatleaf Knotweed need?
Pleatleaf Knotweed grows best in part sun conditions.
When does Pleatleaf Knotweed bloom?
Pleatleaf Knotweed blooms in July, August, and September.
Where is Pleatleaf Knotweed native?
Pleatleaf Knotweed (Polygonum tenue) is native to AL, AR, CT, DE and 30 more states, per the World Checklist of Vascular Plants (Kew).
What pollinators does Pleatleaf Knotweed attract?
Pleatleaf Knotweed draws bees and beetles.
Is Pleatleaf Knotweed HOA-friendly?
Pleatleaf 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 World Checklist of Vascular Plants (Kew). Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.

If something looks wrong

Common plant problems, and what to check first

These come up on almost any plant. Each guide lists the likely causes in the order they are worth ruling out, with one thing to check before you act on any of them, and links to the source it came from.

See all plant problem guides

Ready to grow Pleatleaf Knotweed? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.

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