Q: We have Virginia buttonweed overwhelming our centipede lawn. We re-seeded the lawn last year.
A: Virginia buttonweed is extremely tough to control. It does not respond to most weed killers. It is a perennial plant and will resprout from root pieces if you dig it up. If you did any soil disturbance before seeding the lawn, that could explain why you have so much of it now. Long-buried seed may have been stimulated to germinate by being brought to the soil surface. Homeowner weed control products that contain carfentrazone are useful but must be applied more than once. I would spray in mid-April and again in mid-May. Since centipede grass is sensitive to herbicides in hot weather, only use spot sprays after early summer. I predict it will take two years of treatment to get good control.