For New Jersey fall lawns, two fertilizer treatments are ideal. To help the grass recover from severe summer use and heat damage, use the early treatment between late August and early September. At this time of year, slow-release fertilizer is ideal since it will nourish the grass for several weeks. Later autumn fertilization is best administered in late October or early November, and it should be a fast-release mix to provide the grass a good boost of nourishment before the roots become dormant.