Weeds of Container Nurseries in the United States

Several species of woodsorrel are common in container nurseries, growing best in spring or fall in warmer climates but plants will be present year round. These plants are perennial, spreading by rhizomes and stolon, as well as by seeds. Seeds are forcefully expelled up to 16 feet away. Seeds have no dormancy and may germinate quickly. Flowers are bright yellow. Plants harbor whitefly and mites. Identifying characteristics include: heart-shaped leaflets on trifoliolate leaves and cylindrical seed pods. Leaves resemble those of clover, but woodsorrel is not in the legume family. Sanitation is critical in controlling woodsorrel in nursery crops, especially in propagation areas. Do not let plants go to seed in the nursery. Inspect all new plant materials for infestations of this weed. Woodsorrel from seed is well controlled by most preemergence herbicides. Once established in a pot, it is nearly impossible to completely remove woodsorrel rhizomes and stolons.