North America Native Plant

Fowler’s Knotweed

Botanical name: Polygonum fowleri fowleri

USDA symbol: POFOF7

Life cycle: perennial

Habit: forb

Native status: Native to Alaska âš˜ Native to Canada âš˜ Native to the lower 48 states âš˜ Native to St. Pierre and Miquelon  

Synonyms: Polygonum buxifolium Nutt. ex Bong. (POBU5)   

Fowler’s Knotweed: A Mysterious Native with Limited Garden Presence If you’ve stumbled across the name Fowler’s knotweed (Polygonum fowleri fowleri) in your native plant research, you’ve discovered one of gardening’s more enigmatic species. This perennial forb has a fascinating distribution story, but finding practical growing information? Well, that’s where things ...

Fowler’s Knotweed: A Mysterious Native with Limited Garden Presence

If you’ve stumbled across the name Fowler’s knotweed (Polygonum fowleri fowleri) in your native plant research, you’ve discovered one of gardening’s more enigmatic species. This perennial forb has a fascinating distribution story, but finding practical growing information? Well, that’s where things get interesting.

What Is Fowler’s Knotweed?

Fowler’s knotweed is a perennial herbaceous plant belonging to the knotweed family. As a forb, it lacks significant woody tissue and maintains its life cycle through underground structures that survive winter’s harsh conditions. You might also encounter it listed under its synonym Polygonum buxifolium, though taxonomic references for this particular subspecies remain somewhat murky in horticultural literature.

Where Does It Call Home?

Here’s where Fowler’s knotweed gets truly impressive – its native range spans an enormous swath of northern North America. This hardy native calls home to:

  • Canadian provinces: British Columbia, Manitoba, New Brunswick, Nova Scotia, Ontario, Prince Edward Island, Quebec, Yukon, Northwest Territories, Labrador, and Newfoundland
  • U.S. states: Alaska, California, Maine, Ohio, Oregon, Washington, and Wisconsin
  • Even St. Pierre and Miquelon

This extensive range suggests a plant that’s remarkably adaptable to various climatic conditions, from coastal regions to interior landscapes.

The Garden Reality Check

Here’s where I need to be honest with you: despite its impressive native credentials, Fowler’s knotweed is practically invisible in the gardening world. Information about its appearance, growing requirements, wildlife benefits, and cultivation practices is extremely limited in horticultural sources. This isn’t necessarily a red flag – it simply means this species hasn’t made the leap from wild native to garden-worthy plant.

Should You Grow It?

The lack of cultivation information presents a challenge for gardeners interested in this native species. While its extensive natural range suggests it could be hardy and adaptable, without specific growing requirements, plant size information, or proven garden performance, it’s difficult to recommend for most landscapes.

If you’re determined to work with native knotweeds, you might consider exploring other Polygonum species that have better-documented garden performance and clearer cultivation guidelines.

What We Can Assume

Based on its northern distribution, Fowler’s knotweed likely:

  • Tolerates cold temperatures well (given its presence in Alaska and northern Canada)
  • Adapts to various soil conditions (considering its wide geographic range)
  • Functions as part of native ecosystems across its range

The Bottom Line

Fowler’s knotweed represents one of those fascinating native plants that remains largely unexplored in cultivation. While its extensive native range makes it an intriguing species from a botanical perspective, the lack of horticultural information makes it a challenging choice for most gardeners.

If you’re passionate about growing lesser-known natives and enjoy gardening adventures, this species might appeal to you – but be prepared for some trial and error. For most gardeners seeking reliable native plants with known garden performance, exploring well-documented native alternatives in the knotweed family or other native forbs might prove more successful.

Fowler’s Knotweed

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 fowleri B.L. Rob. - Fowler's knotweed

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