Darrell Blackwelder: Virginia buttonweed can be tough to kill

Published 12:00 am Sunday, September 19, 2021

Earlier this week, I had a question from a homeowner having problems with an aggressive weed in his lawn. It was growing rampant in his entire neighborhood and was curious what it was and how to eliminate the problem weed. The weed was identified as Virginia buttonweed (Diodia virginiana), a herbaceous perennial grass-like weed that grows prostrate in many lawns. The leaves of Virginia buttonweed look appear pale and yellow at this time period due to an unknown virus that does not kill the weed. Virginia buttonweed produces a crop of very small, white flowers early spring and again in the fall.

The owner had tried to use a broadleaf weedkiller that is designed to kill broadleaf weeds several times, but, unfortunately, herbicides applications on this weed late in the growing season are often not effective. Broadleaf weed control herbicides should be applied in early summer when the weed is newly emerging. This weed thrives in weak and thinning turf with compact and poorly drained soils. Excessive irrigation or over abundant rainfall experienced earlier this spring exacerbates the problem. Proper turf maintenance with correct fertilization, mowing heights and minimal irrigation encourages dense fescue growth and therefore reduces germination of Virginia buttonweed and other weeds. Unfortunately, Virginia buttonweed is a tough perennial and it may take multiple applications and a lot of patience for sufficient control. More detailed information can be found at https://www.turffiles.ncsu.edu/weeds-in-turf/virginia-buttonweed/.

Darrell Blackwelder is the retired horticulture agent and director with the North Carolina Cooperative Extension Service in Rowan County. Contact him at deblackw@ncsu.edu .