Persicaria

Knotweed. Bistort, Smart Weed

Annuals and perennials with an erect or decumbent growth habit, or occasionally rhizomatous. The leaf under-surface is commonly a lighter colour than the top. Flowers have 4 or 5 petals and are commonly pink or white, but occasionally greenish.

Uses

Ornamental plants.  Foliage of some species can cause an allergic reaction on the skin of animals and people. They may become invasive weeds.

Culture

They grow best in full sun or semi-shade in moist or wet soils, but well-drained soil is preferred. They will tolerate a wide range of soil pH and texture conditions.

Propagation

They are easy to propagate by division in spring or autumn.

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