I recently use Bayer Advanced Lawn Weed and Crabgrass killer on my very healthy lawn (perennial rye, tall fescue, red fescue, and bluegrass) About 3 days later there was a brown spot everywhere we used the product. I live in central PA and we have had lots of rain this year. The lawn was thick and healthy. The product said it was safe to use on lawns, but it turn mine brown. What caused this and how can I restore the green.
Weed killers should not be applied when it is hot out…above 80° or so. The weed killer can burn the grass if applied during hot weather. Water the lawn to wash away the weed killer and the lawn may recover. July is a bad time to apply weed killer due to the potential for high temperatures.