Polygonum spp.

There are several native species of Polygonum that resemble Japanese knotweed in the seedling stage. Japanese knotweed is distinguished by greater overall height, and vigorous growth of stout rhizomes.

This plant is a popular ornamental, and many cultivated varieties are produced by the nursery industry. Varieties may be difficult to distinguish, but most share the same invasive characteristics and will respond to the same treatment as the parent plant.

Landscape Alternatives

These native plants are suitable substitutes for Japanese Knotweed in the landscape.

Goat’s-beard (Aruncus dioicus) has tall stalks topped with foamy white panicles of tiny flowers in early summer. Attracts bees.

Culver’s Root (Veronicastrum virginicum) is an upright perennial (4-5 feet) with numerous, narrow spires of tiny white flowers emerging from axils of the whorled leaves throughout the month of June. Attractive to bees and butterflies.

White Snakeroot (Ageratina altissima) flowers in fall with dense showy heads of small white flowers on tall stems. Attracts bees and butterflies.

Black Snakeroot (Cimicifuga racemosa) flowers in early summer in shade producing long spires of white flowers on tall stalks. Attracts bees and butterflies.

Summersweet (Clethra alnifolia) is a summer flowering shrub with fragrant spikes of white to pink flowers. Attracts bees and butterflies.

Virginia Sweetspire (Itea virginica) is another summer flowering shrub with long drooping racemes of white flowers attractive to bees.