When to Fertilize Your Lawn in Fall (and How Much to Use)

For cool-season lawns, September and November are the two best times to fertilize, according to Purdue University turfgrass specialist Aaron Patton. Put down about 1 lb of nitrogen per 1,000 sq ft in September, once daytime highs are no longer in the 90s °F. Then apply 0.5 to 1 lb in the first few weeks of November, near or after the last mowing while the grass is still green.

Free calculator: our free lawn calculator works out fertilizer from the N-P-K numbers on your bag, plus grass seed and plant spacing. No sign-up.

Fall fertilizer schedule for cool-season lawns

September — 1 lb of nitrogen per 1,000 sq ft, after daytime highs drop out of the 90s °F. Purdue suggests a product with some quick-release and some slow-release nitrogen.

First few weeks of November — 0.5 to 1 lb of nitrogen per 1,000 sq ft, near or after the last mowing, while the lawn is still green. Purdue says quick-release nitrogen works best here, because the grass has to take it up before winter.

Missed September? Purdue's second window, early November, is still ahead.

This schedule is for cool-season grasses such as Kentucky bluegrass, tall fescue and perennial ryegrass. Warm-season lawns such as Bermuda or St. Augustine follow a different calendar, so check with your state's extension service.

How much fertilizer to buy

Divide the nitrogen you want by the first number on the bag. Pounds of product for 1 lb of nitrogen per 1,000 sq ft, and for a 5,000 sq ft lawn:

10-10-10 — 10 lb per 1,000 sq ft; 50 lb for 5,000 sq ft

16-4-8 — 6.3 lb; 31 lb for 5,000 sq ft

24-0-6 — 4.2 lb; 21 lb for 5,000 sq ft

32-0-4 — 3.1 lb; 16 lb for 5,000 sq ft

46-0-0 — 2.2 lb; 11 lb for 5,000 sq ft

For a November feeding at 0.5 lb of nitrogen, halve these amounts. Measure your lawn and plug in your bag in the free lawn calculator.

Tips for an even spread

Use the setting on the bag. Many fertilizer bags list spreader settings for common spreaders.

Sweep up strays. Granules that land on a driveway or sidewalk belong back on the grass.

Too late to seed? Bare spots can be dormant seeded from late fall into winter: see how to dormant seed a lawn.

Spreaders for fall feeding (#ad)

Scotts Turf Builder EdgeGuard DLX Broadcast Spreader — comes pre-calibrated and holds up to 15,000 sq ft of Scotts product, per the maker. Its side shield keeps fertilizer off beds, driveways and sidewalks. See it on Amazon

EarthWay 2600A-PLUS Fertilizer Spreader — a 40 lb hopper on all-terrain pneumatic tires, with a rust-proof poly hopper, epoxy-coated steel frame and 3-hole drop shut-off, per the maker. A full hopper of 24-0-6 covers about 9,600 sq ft at 1 lb of nitrogen. See it on Amazon

As an Amazon Associate, Curb Calc earns from qualifying purchases.

Fall lawn fertilizer FAQ

When should I fertilize my lawn in fall? For cool-season grass, in September and again in the first few weeks of November, per Purdue University's turf program.

How much fertilizer per 1,000 sq ft in fall? 1 lb of nitrogen in September and 0.5 to 1 lb in November. For a 24-0-6 bag, 1 lb of nitrogen is about 4.2 lb of product.

Should I use slow-release fertilizer in fall? Purdue favors more quick-release nitrogen in fall, and quick-release for the November feeding.

Is it too late to fertilize if I missed September? No. The November feeding, near the last mowing while the grass is still green, is the second of Purdue's two fall windows.

Sources: Purdue University Turfgrass Science, Fall Fertilization.