We have been using the EXACT same Scott's weed and feed on our lawn since 1983. This year we have burned out area's of our lawn. NOT weeds grass. I don't know if there was a cross contamination at the factory. In fact we bought two bags, used partial one on my mother-in-laws (she has a very small yard) the rest on one area of our yard and second bag on ours. The partial bag no problem, the second full bag burn out everywhere. Same spreader settings as we have always used. DDON'T second bag User's recommendation: DON'T USE SCOTT'S.