Bahiagrass (Paspalum notatum Flueggé) is a warm-season, perennial grassy weed common throughout Louisiana. It can tolerate a wide range of soil types, but it is typically found growing along highways and in lawns with dry, compacted soil. It produces seeds quite abundantly and can also spread through rhizomes (underground stems), creating unsightly clumps in turfgrass. Because of its aggressive nature and drought tolerance, bahiagrass is competitive with turfgrass and difficult to control in the lawn.
Bahiagrass can be identified by its coarse light-green leaves. Its leaves sometimes appear folded and are sharply pointed, and its seed heads are composed of two spikes (stems of clustered flowers) that are attached at the top of the flower stalk to form a distinct “V” shape. The spikes are lined with tiny dark-brown to black flowers. Bahiagrass has a deep and extensive root system with robust pink to red rhizomes (underground stems).
For more information on Bahiagrass identification and characterization visit the USDA Plants Database at https://plants.usda.gov.
The best way to prevent or reduce weed encroachment is to maintain a healthy lawn through regular mowing and proper fertilization and soil pH management. Properly maintaining a lawn through these cultural practices promotes dense and vigorous turfgrass and allows the turfgrass to better compete with weeds. Below are the recommended mowing heights and nitrogen fertility rates recommended for each turfgrass species. In addition to these lawn care practices, manual removal of weeds may also be necessary.
In addition to cultural practices, herbicide applications may be required to achieve effective weed control. Apply post-emergent herbicides in late spring when bahiagrass begins to emerge, followed by a sequential application in the summer. Metsulfuron methyl is highly effective on Pensacola bahiagrass, which is the most common type of bahiagrass infesting lawns in Louisiana. When applying any type of herbicide, you must follow the manufacturer's labeled directions.
For more information regarding pesticides for turfgrass please reference the Louisiana Suggested Chemical Weed Control Guide.
For information regarding weed identification and control options please contact your local LSU AgCenter Extension Parish Office. To find your local LSU AgCenter Extension Parish Office visit here.