Green Thumb® GT58106 Winterizer Lawn Fertilizer w/ Surfcote, 32-0-10, 15000 Sq.Ft.Green Thumb Winterizer helps your lawns to survive the winter stress. Encourages a stronger, deeper root system. Easy to use. No waiting necessary, lawn is safe to walk on immediately after application. Includes 2% iron for deep greening and 50% controlled release nitrogen. Continuously feeds for up to 16 weeks. Helps your lawns to survive the winter stress Encourages a stronger, deeper root system Easy to use 2% iron for deep greening 50% controlled