Fall is the best time to fertilize fescue lawns. During the fall, fescue grass uses fertilizer to develop a stronger root system and store energy for the following year. A lawn adequately fed in the fall will be healthier and better looking the entire year. As a bonus, it will require less fertilization in the spring. Tree Top will help make you the envy of the neighborhood with a dark green lush spring lawn. We recommend applying Ferti-lome Winterizer in September, October, and November. Wait at least 30 days between applications.