Green Thumb 32-0-10 Winterizer. Easy to use. Helps Lawns Survive the Winter Stress. Encourages a Stronger, Deeper Root System. Thick, Green Lawn this Fall & Quicker Spring Green-up. 2% Iron for Deep Greening. 50% Controlled Release Nitrogen. Covers up to 5,000 square feet. Continuously feeds for up to 16 Weeks!