In the heart of South Florida’s vegetable production, these weedy competitors are a primary target of growers’ ire. Left uncontrolled, these weeds can take over fields and rob crops of valuable yields.
1. Common lambsquarters (Chenopodium album)
Common lambsquarters, a member of the goosefoot family, is a broadleaf annual weed common in vegetable and agronomic croplands, roadsides, and disturbed areas. It is an erect, branched plant that can grow from 1 to 6 feet tall. The stem is hairless, vertically ridged, and often has maroon or red stripes. The leaves alternate along the stem with the lower leaves wavy and margined to somewhat lobed, while the upper are often narrower.
The undersurface of younger leaves have a white to grayish-mealy coating. Individual flowers are small, inconspicuous, greenish-gray, mealy, and arise from the ends of stems and leaf axils. A single plant produces thousands of round shiny black or sometimes brown, oval, and flattened seeds, which can persist for years in the soil. This weed species often emerges during winter months, and is found in many fields in the spring. Treatment of vegetables with labeled herbicides early in the season provides good control of common lambsquarters.