Fertilizers come in two varieties quick release and slow release quick release fertilizer release all the nutrients once applied. The lawn tends to run through this food source in a couple of weeks making it great for a quick green up but suboptimal for consistent health of the lawn. Slow release fertilizers continue to feed the lawn for a longer period of time as the nutrients are slowly released. This will feed the lawn for up to six weeks and provides a much healthier food source for the lawn.