Organic Horticulture in the Mid-Atlantic/Pinkweeds

Persicaria spp. (Pinkweeds, Lady's Thumb) Pinkweeds, otherwise known as smartweeds or lady's thumbs are any of a number of plants in the genus Persicaria (formerly Polygonum), including both native and invasive species. The weedy species are all annual plants with simple, smooth-margined leaves, and often have a dark marking (a "lady's thumbprint") in the center of each leaf. The leaves and branches are alternate, with each node somewhat swollen and covered by a thin sheath (the old genus name "Polygonum" roughly means "many-knees"). Pinkweeds have a fibrous root system and may root at the nodes where the stems touch the ground. Grubbing out is generally easy, and cultivators may be used on young plants. With the exception of the young seedlings, plants should be composted only in hot systems, since the plants can continue to grow and/or set seed in cold piles. Some species of Persicaria are grown as garden plants as well, though these species tend to look quite different from the weedy types. thumb|225px|Along a garden edge thumb|225px|P. maculosa, showing rootthumb|225px|Closeup of stem node Persicaria