10/01/2026
October marks the end of most summer fertilizer restrictions in Hillsborough County. Nitrogen and phosphorus are generally restricted from June 1 through September 30, while nutrients such as potassium, magnesium, manganese, and iron may still be applied.
After a nitrogen-free summer, your lawn may look pale. Nitrogen supports photosynthesis and helps turfgrass produce chlorophyll—the pigment responsible for its green color. October and early
November are ideal times to fertilize before cooler temperatures and shorter days naturally slow growth.
Some fall lawn-care recommendations:
• Use a slow-release, balanced fertilizer with approximately a 2:1 nitrogen-to-potassium ratio, such as 16-0-8 or 24-0-11. Avoid phosphorus unless a soil test shows a deficiency.
• If your soil test indicates low potassium, consider a 1:1 nitrogen-to-potassium ratio, such as 15-0-15 or 18-0-18.
• Choose a fertilizer containing at least 50% slow-release nitrogen.
• Apply your final annual fertilizer application by mid-November.
• Wait until late March, after the turf begins greening naturally, to make the first spring application.
• Follow the fertilizer label’s irrigation instructions. Granular fertilizers typically require light irrigation after application.
• Apply no more than 1 pound of nitrogen per 1,000 square feet at one time and no more than 4 pounds per 1,000 square feet during the growing season.
•Reduce irrigation during the cooler months. If there has been no rain, watering approximately once every 10–14 days may be sufficient. Also, check that your irrigation rain shutoff device is working properly.
• Watch for fall fungal diseases such as large patch. Excessive water and high nitrogen applications can worsen many turf diseases. Learn more about [turfgrass disease management].
• If your lawn has a history of winter w**ds—including annual bluegrass, chickw**d, henbit, lawn burw**d, or wild geranium—consider applying a preemergent herbicide. See our [winter w**d control timeline] for more information.
All this info was pulled from the following: Fall Lawn Care After the Fertilizer Restricted Period - UF/IFAS Extension Hillsborough County
