Southern lawns most troublesome weed: Virginia buttonweed (7-5-10)

Virginia buttonweed (Diodia virginiana), once established in a lawn, is very difficult to control since it reproduces by seed, fleshy roots and from stem fragments. It is a spreading perennial broadleaf weed with opposite, lance shaped leaves producing small, four-lobed white flowers when in bloom that eventually develop small football shaped seed pods.

Virginia buttonweed favors moist to wet areas, but can spread throughout the lawn. Pre-emergent herbicides provide only fair control of new seedlings and are ineffective from spreading by vegetative plant parts. Therefore, post-emergent herbicide applications are the most effective means of management.

Products containing phenoxy (hormonal) type chemicals such as 2,4-D, mecoprop, dicamba, fluroxypyr, etc. are effective if applied several times during the growing season. The sulfonyl-urea type chemicals, including chlorsulfuron, metsulfuron, trifloxysulfuron, sulfosulfuron, etc., are also very effective at extremely low use rates.

Caution should always be taken to calibrate application equipment and apply herbicides accurately to prevent turf injury. Read product labels carefully and completely as not all products can be applied to all warm-season turf species. More specific information on controlling weeds in home lawns can be found in the turf section of Extension publication #1532 Weed Control Guidelines for Mississippi.

Published July 5, 2010

Dr. Wayne Wells is an Extension Professor and Turfgrass Specialist. His mailing address is Department of Plant and Soil Sciences, Mail Stop 9555, Mississippi State, MS 39762. wwells@ext.msstate.edu