Pigweed is a summer annual broadleaf weed that is also called Rough Pigweed, Amaranth Pigweed, Green Amaranth, Careless Weed and Amaranthus retroflexus.
Pigweed can be identified as a vertical, freely branching broadleaf weed featuring stout, vertically growing stems. The lower part of the plant is thick and smooth, whereas the upper part is often branched and very hairy. Pigweed also has blades that are dull green on top and hairy underneath. The veins on the lower surface are prominently white. Pigweed reproduces by seeds produced from late summer throughout fall—or until severe frost sets in.
This broadleaf weed often grows in bare or undeveloped locations and thrives near the banks of rivers, streams and lakes. In residential yards, Pigweed is commonly found in bare or undeveloped patches of your lawn. It can be found throughout much of the continental United States.
Proper cultural practices, such as proper mowing and watering, can help prevent Amaranthus retroflexus by creating dense grass, which inhibits this broadleaf weed's ability to grow. Physical removal (i.e., pulling weeds) can be effective, though you run the risk of spreading the seeds to additional areas of your lawn and landscaping.