What is the difference between Roundup and Roundup for Lawns? Many people have asked me about a new lawn herbicide advertised on television this year called Roundup for Lawns and why it won’t kill their lawn. The quick answer is that it is really not Roundup as you may know it. Many people are familiar with Roundup, an herbicide that contains the active ingredient glyphosate. If Roundup herbicide is sprayed on a lawn it will kill both the weeds and the lawn. Roundup herbicide is a product of Monsanto. Roundup for Lawns is a new lawn herbicide from The Scott’s Company and this product is not registered for use in New York State. Roundup for Lawns does not contain glyphosate (the active ingredient in Roundup herbicide). The active ingredients in Roundup for Lawns are MCPA, dicamba, quinclorac and sulfentrazone. These ingredients will control many broadleaf, grass, and sedge weeds in lawns without killing the desirable turf grasses. If you go to the store to purchase Roundup for Lawns you will not find this product. Do not use Roundup herbicide as a substitute or you will kill your entire lawn. If this mistake is made you will need to go back to the store to buy grass seed. By Mike Hunter, Field Crops Specialist, Cornell University May 6, 2017