lAWN POISONING

Nothing much you can do. If it is already going brown, means it's too late. It pays to read labels! I don't know what kind of grass it is, I always put runners for my lawn, so if something goes wrong, I just plant new runners from another area where the grass is growing into the garden beds for instance. Ask your local nursery what the best lawn for your area is and if you can sow some more now. You can pull trenches with a knife or spade and throw in seeds, it is a long job.Alternatively buy some instant lawn tiles and put them over these. The roundup won't affect the new lawn anymore. Sorry for you, I don't know what else you could do.