How late in the fall can fertilizer be applied to a lawn?

A fertilizer, which does not have a high nitrogen analysis, can be applied through the months of September, October or November. At this time of year, although some nitrogen is important, phosphorus and potassium are critical. The end of October or early November is a perfect time for applying the fall fertilizer, as the plant has the time to benefit from the application and still prepare itself for the harsh upcoming winter months. Fertilizing too late in the season leaves the turfgrass tender and lush. The turf is then potentially susceptible to damage from winterkill and cold temperature diseases such as pink patch and/or pink or grey snow mold.