Choose a fertilizer that will last longer and require fewer applications in the spring to ensure a healthy lawn this season. A section titled "guaranteed analysis" is located on the back of the packaging and contains all of the information you need about the fertilizer. However, keep in mind that there are nitrogen sources that are both fast-release and slow-release. Specifically, you seek nitrogen with a slow-release or a regulated, fast release and is granules or liquid. Some examples of specialized varieties include urea in liquid form, sulfur-coated urea, polymer-coated urea, and IBDU.  Organic nitrogen sources that can be slow-released are available if you desire a more natural, less artificial source of nitrogen than synthetic nitrogen sources. The fast-release fertilizer provides both quick color and long-lasting nitrogen, with the most high-quality lawn fertilizers blend sources that release nutrients quickly and gradually.