Jeffrey Beasley, Strahan, Ronald E., Sanders, Kayla
Yellow woodsorrel (Oxalis stricta L.), or oxalis, is a perennial weed common throughout Louisiana. It is easily distinguished by its heart-shaped leaflets, which occur in sets of three per leaf. Yellow woodsorrel produces flowers in the spring and spreads through seed. It is commonly found growing in areas where turfgrass is thin and weak. It has an upright, mat-forming growth habit in turfgrass.
Yellow woodsorrel has green to yellow-green leaves with hairy edges. Leaves are made up of three heart-shaped leaflets, which are partially folded along the middle vein. Yellow flowers with five petals extend from the plant on long stalks that usually bend before branching outward. Flowers mature into long, slender fruiting capsules that resemble okra. Yellow woodsorrel typically grows in small, upright bunches but can also form dense mats. For more information on yellow woodsorrel identification and characterization, visit the USDA Plants Database at https://plants.usda.gov.
Bunched growth habit
The best way to prevent or reduce weed encroachment is to maintain a healthy lawn through proper fertilization and soil pH management and regular mowing. Properly maintaining a lawn through these cultural practices promotes dense and vigorous turfgrass, allowing it 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.
|Bermudagrass||1 - 2 inches||Up to 3 pounds|
|Centipedegrass||1 - 2.5 inches||Up to 2 pounds|
|St. Augustinegrass||2.5 - 3 inches||Up to 3 pounds|
|Zoysia||1 - 2.5 inches||Up to 2 pounds|
In addition to cultural practices, herbicide applications may be required to achieve effective weed control. However, yellow woodsorrel can be very difficult to manage with pre-emergence and post-emergence herbicides. The most effective herbicides on yellow woodsorrel contain the active ingredient metsulfuron.
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 at the LSU AgCenter website, www.lsuagcenter.com.
|Pre-emergence Herbicide Active Ingredients|
| dimethenamid + pendimethalin||x||x||x||x|
|Post-emergence Herbicide Active Ingredients |
|metsulfuron + dicamba||x||x||x||x|
|metsulfuron + sulfentrazone||x||x||x||x|
|thiencarbazone + iodosulfuron + dicamba||x||x||x||x|
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 www.lsuagcenter.com.