By late summer, heavy Virginia buttonweed populations can form a dense mat that can kill large areas of the lawn. Single herbicide applications, especially late-season, have not been effective on mature Virginia buttonweed. ... In the hot summertime, metsulfuron (MSM, Mansion) or Celsius herbicides should be applied.

What herbicide will kill Virginia buttonweed?

According to research trials , herbicides that contain the active ingredients 2,4-D, dicamba, mecoprop and carfentrazone (Speed Zone Southern, Weed Free Zone, Weed B Gon) have been effective in suppressing emerging perennial plants and killing the first flush of buttonweed seedlings when applied in spring.

How do I get rid of Virginia buttonweed?

Because of the way it can spread by seed and rhizomes, hand pulling virginia buttonweed is not going to successfully get rid of it. The best option is using a post-emergent herbicide and spot spraying it rather than using a blanket application as this will risk damaging the desired turf.