Broadleaf Panicum is a summer annual grassy weed that is also known as Tropic Panicum, Dominican Panicum, Broadleaf Signalgrass or by its scientific name, Panicum adspersum.
Broadleaf Panicum can be identified as a summer annual grassy weed that sometimes bends and roots at the lower nodes. It features leafy stems growing upright to ascending and its ligule is relatively small. This lawn weed has broad, flat blades that are often covered with fine hairs, and its leaf sheaths are also hairy (often in lines along the edges). Broadleaf Panicum produces more lawn weeds through seeds, forming seed heads with ascending branches. It also produces flowers that are purple to greenish-yellow in color with obscure, rectangular lines.
This grassy weed prefers disturbed, developed and open areas and is often found in croplands, lawns and landscaped areas. Broadleaf Panicum thrives in the far southwestern parts of the United States but these lawn weeds can also be found in the upper northeast parts of the country (including Pennsylvania and New Jersey). These grassy weeds are also summer annuals, meaning they begin to grow (germinate) in the spring, mature in the summer and then produce seeds and die by the fall or first hard frost—an entire life cycle completed within 12 months.
Because these grass-like weeds can root at the nodes, Broadleaf Panicum can easily spread throughout a lawn or landscaped area that is thin or poorly maintained. Cultural weed control methods—such as hand-pulling weeds or proper watering and mowing—are not particularly effective in removing this lawn weed. For weed removal, professionally applied weed control treatments are the best option.