North America Native Plant

Halberdleaf Tearthumb

Botanical name: Polygonum arifolium

USDA symbol: POAR6

Life cycle: annual

Habit: vine

Native status: Native to Canada âš˜ Native to the lower 48 states  

Synonyms: Persicaria arifolia (L.) Harolds. (PEAR13)  âš˜  Polygonum arifolium L. var. lentiforme Fernald & Grisc. (POARL3)  âš˜  Polygonum arifolium L. var. pubescens (Keller) Fernald (POARP)  âš˜  Tracaulon arifolium (L.) Raf. (TRAR6)   

Halberdleaf Tearthumb: A Native Wetland Wonder for Your Rain Garden Meet halberdleaf tearthumb (Polygonum arifolium), a native annual that’s perfectly suited for gardeners looking to create authentic wetland habitats or tackle those persistently soggy spots in their landscape. While its common name might sound a bit intimidating, this native forb ...

Halberdleaf Tearthumb: A Native Wetland Wonder for Your Rain Garden

Meet halberdleaf tearthumb (Polygonum arifolium), a native annual that’s perfectly suited for gardeners looking to create authentic wetland habitats or tackle those persistently soggy spots in their landscape. While its common name might sound a bit intimidating, this native forb is actually a valuable addition to the right garden setting.

What Makes Halberdleaf Tearthumb Special

This distinctive native plant gets its name from its arrow-shaped (halberd-like) leaves and the backward-pointing prickles along its stems that can catch on clothing—hence the tearthumb moniker. Despite its somewhat prickly personality, it’s a legitimate native species with an important ecological role.

As an annual forb, halberdleaf tearthumb completes its entire life cycle in one growing season, producing small clusters of white to pinkish flowers that may not win any beauty contests but serve an important purpose for pollinators. The plant has a sprawling, somewhat climbing growth habit that allows it to weave through other vegetation.

Where It Calls Home

Halberdleaf tearthumb is native throughout much of eastern North America, thriving in states and provinces from Nova Scotia and New Brunswick down to Georgia and Louisiana, and west to Minnesota and Missouri. You’ll find it naturally occurring in Connecticut, Delaware, District of Columbia, Georgia, Illinois, Indiana, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Vermont, Virginia, Washington, West Virginia, and Wisconsin, plus several Canadian provinces.

The Ultimate Wetland Plant

Here’s what makes halberdleaf tearthumb truly special: it’s classified as an obligate wetland species across all regions where it grows. This means it almost always occurs in wetlands and has adapted specifically to thrive in consistently moist to wet conditions. If you have a boggy area, seasonal flooding, or want to create a rain garden, this plant is practically designed for the job.

Should You Grow Halberdleaf Tearthumb?

Consider growing it if you:

  • Have consistently wet or boggy areas in your landscape
  • Are creating a rain garden or wetland restoration project
  • Want to provide habitat for native wildlife and pollinators
  • Prefer low-maintenance plants that thrive in difficult conditions
  • Are working on a naturalized landscape design

Think twice if you:

  • Have well-drained garden beds
  • Prefer formal or highly manicured landscapes
  • Want showy, ornamental flowers
  • Are concerned about plants with aggressive spreading habits

Growing Halberdleaf Tearthumb Successfully

Growing Conditions:

  • Sunlight: Full sun to partial shade
  • Soil: Consistently moist to wet soils; tolerates periodic flooding
  • USDA Hardiness Zones: 3-9
  • Moisture: High moisture requirements—not drought tolerant

Planting and Care Tips:

  • Direct seed in fall or early spring when soil is naturally moist
  • No special soil preparation needed if planting in naturally wet areas
  • Ensure consistent moisture throughout the growing season
  • Allow space for spreading—this plant can be quite vigorous
  • Best suited for naturalized areas rather than formal garden beds

The Bottom Line

Halberdleaf tearthumb isn’t going to win any most beautiful garden plant awards, but it excels in its specialized niche. If you’re working with wet areas, creating wildlife habitat, or restoring native ecosystems, this tough little annual can be exactly what you need. Its small flowers provide nectar for various pollinators, and its dense growth offers shelter for small wildlife.

Just remember that this plant is happiest—and most manageable—when grown in appropriate wetland conditions. In the right setting, halberdleaf tearthumb transforms from a potential garden nuisance into a valuable native ally that helps create authentic, functional wetland habitats right in your own backyard.

Wetland Status

The rule of seasoned gardeners and landscapers is to choose the "right plant for the right place" matching plants to their ideal growing conditions, so they'll thrive with less work and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection is. While tags list watering requirements, there's more to the story.

Knowing a plant's wetland status can simplify the process by revealing the interaction between plants, water, and soil. Surprisingly, many popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. Also, it helps you make smarter gardening choices and grow healthy plants with less care and feeding, saving you time, frustration, and money while producing an attractive garden with greater ecological benefits.

Regions
Status
Moisture Conditions

Arid West

OBL

Obligate Wetland - Plants with this status almost always occurs in wetlands

Atlantic and Gulf Coastal Plain

OBL

Obligate Wetland - Plants with this status almost always occurs in wetlands

Eastern Mountains and Piedmont

OBL

Obligate Wetland - Plants with this status almost always occurs in wetlands

Great Plains

OBL

Obligate Wetland - Plants with this status almost always occurs in wetlands

Midwest

OBL

Obligate Wetland - Plants with this status almost always occurs in wetlands

Northcentral & Northeast

OBL

Obligate Wetland - Plants with this status almost always occurs in wetlands

Western Mountains, Valleys, and Coast

OBL

Obligate Wetland - Plants with this status almost always occurs in wetlands

Halberdleaf Tearthumb

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Caryophyllidae

Order

Polygonales

Family

Polygonaceae Juss. - Buckwheat family

Genus

Polygonum L. - knotweed

Species

Polygonum arifolium L. - halberdleaf tearthumb

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA