We recommend waiting until mid-May to fertilize for the vast majority of do-it-yourselfers, while professional lawn care operators often apply fertilizer early in the spring with the preemergence herbicide. These two seem to contradict each other. We know that a very low rate of N applied in the spring will green up the turf quickly while having little or no negative effects in the future. The secret is using a very low rate (0.4-0.7 lbs N/1000 sq. ft). Professionals have the products and the technology available to easily and accurately deliver these low rates. However, for the typical do-it-yourselfer, it is very difficult and likely impossible to find low N products and then apply these products at low rates. More often than we’d like to admit, the results do-it-yourselfers get with spring N looks like the photo below. Therefore we error on the side of safety and recommend no N until mid-May for most do-it-yourselfers.