In this guide
Short answer
Fall is when lawns get made. For cool-season grass, the work you do between mid-August and November decides how the lawn looks next June. For warm-season grass, fall is about getting into winter dormancy healthy, and mostly about what not to do.
This checklist is based on fall guidance from Iowa State, Purdue, Nebraska, Illinois, Clemson and UGA extension services. I look after my own lawn with EGO battery tools, and fall is the busiest stretch of the year for them: mowing, mulching leaves and blowing off the beds.
Not sure which grass you have? Cool-season vs warm-season grass explains it in a few minutes.
Cool-season lawn: fall checklist
Kentucky bluegrass, tall fescue, perennial ryegrass and fine fescue. This covers most of the northern half of the US and the transition zone.
| When | Task |
|---|---|
| Mid-August to mid-September | Overseed or repair bare spots |
| Late August to early September | First fall feeding |
| Early September | Core aerate |
| Mid-September | Fertilize (up to 1 lb N per 1,000 sq ft) |
| Mid to late September | Lower mowing height gradually |
| Late September to early November | Broadleaf weed control |
| September to November | Mulch or remove leaves |
| Late October to early November | Last mow, when growth stops |
| Early November | Late-fall fertilizer while grass is still green |
1. Overseed thin areas (mid-August to mid-September)
Iowa State and Nebraska both name mid-August to mid-September as the best time to seed cool-season grass. Warm soil speeds germination, fewer weeds sprout, and the new grass has the fall and the following spring to root before summer heat.
Mow down to 1.5 to 2 inches first, open the soil by core aerating, power raking or slit seeding, then spread seed. Iowa State says seed should germinate in 2 to 3 weeks with the top inch of soil kept moist. Full steps are in how to overseed a lawn, and small patches are covered in how to fix bare spots in your lawn.
Plan this first, because it affects everything else. A broadleaf weed killer or pre-emergent can hurt new seedlings, so check each product’s label for its waiting period around seeding.
2. Core aerate (early September)
Iowa State suggests early September, when the soil is moist. Illinois says a few days after a rain works best, since a core aerator can’t push into hard, dry ground.
Use a machine that pulls plugs, roughly 3/4 inch wide and 3 inches long per Iowa State, and skip spike aerators. Aim for 20 to 40 holes per square foot, which usually takes several passes. Leave the cores on the lawn. They break down in a few weeks, or you can drag a mat over them to speed it up.
Aerate before you overseed, and the seed falls into the holes.
3. Fertilize (September)
If you feed a cool-season lawn only once a year, make it fall. Illinois Extension says exactly that.
Timing by source:
- Iowa State: mid-September, no more than 1 lb of actual nitrogen per 1,000 sq ft.
- Nebraska: August 25 to September 5 at 0.75 to 1 lb, then September 15 at 0.5 to 1 lb.
- Illinois: August 15 to September 15 in central Illinois, early August up north, September in the south.
- Purdue: 0.5 to 1 lb per month from late August into early November.
Follow the product label for the rate. If you’re new to reading fertilizer bags, when to fertilize your lawn explains how to turn “pounds of nitrogen” into pounds of product.
4. Kill perennial broadleaf weeds (late September to early November)
Fall is the best time to control dandelions, creeping Charlie, clover and plantain. Illinois explains why: in fall, perennial weeds move sugars down to their roots for winter, and a systemic herbicide goes along with them and kills the whole plant.
Iowa State gives late September to early November and says mixes of two or three active ingredients work better than one. Nebraska suggests September 20 to October 20 and calls spring, shortly after dandelions bloom, the second-best time.
Read and follow the herbicide label, especially if you seeded this fall.
5. Winter annual weeds (September to mid-October)
If your lawn gets henbit or annual bluegrass in spring, those weeds actually sprout in fall. Nebraska suggests a fall pre-emergent from September 1 to October 15 for lawns with a history of them. Don’t use one on areas you just seeded unless the label says it’s safe.
6. Adjust the mower
Iowa State recommends lowering the mowing height from the summer 3 to 3.5 inches back to 2.5 to 3 inches during mid to late September. Do it a notch at a time.
Keep the one-third rule all fall. Grass can grow fast in cool, wet September weather. How to mow a lawn covers heights for every grass.
7. Deal with leaves
A thick mat of leaves blocks light and can smother grass over winter.
Iowa State gives two options. Thin, dry layers can be mulched into the lawn with a mulching mower throughout fall, as long as the pieces are small enough to fall between grass blades. Mow twice if needed. Heavy layers should be raked, blown or bagged and composted.
Illinois adds another option: rake leaves into planting beds, where they help insects that overwinter in leaf litter.
The trick is frequency. Mulching a light layer every week is easy. Mulching six inches of wet oak leaves after a storm is not. A leaf blower handles beds, patios and the heavy piles.
8. Keep watering (until growth stops)
Fall rain is unreliable. Iowa State says turf needs about 1 inch of water a week during active growth, and new seedings and sod need it most.
Their easy test: walk across the lawn. If your footprints stay pressed down instead of springing back, it needs water. Water deeply once or twice a week rather than a little every day, except for new seed. More in how often to water your lawn.
Shut off and drain irrigation lines and outdoor hoses before your first hard freeze.
9. The last mow (late October to early November)
Keep mowing until the grass stops growing. In Iowa, that’s usually late October or early November, when daytime highs stay below 50°F. Nebraska says to keep mowing until the grass stops, often October 15 to November 1.
Illinois Extension says the last mow can be a bit shorter than usual, but don’t scalp it.
10. Late-fall fertilizer (early November)
Purdue recommends a late-fall feeding near or after the last mow, while the grass is still green. That’s usually the first few weeks of November in Indiana. Their rate is 0.5 to 1 lb of nitrogen per 1,000 sq ft using a quick-release source such as urea or ammonium sulfate.
The payoff comes next spring: Purdue says earlier green-up, denser turf and better disease tolerance. Lawns hurt over the summer and newly seeded lawns gain the most. Illinois suggests a winterizer about a week after the last mow.
Don’t spread fertilizer on frozen ground. Purdue is clear on that.
11. Put the tools away right
Before storage, sharpen or replace the mower blade so it’s ready for spring. Clean grass off the deck. For gas mowers, follow the manual for fuel storage. For battery tools, follow the maker’s storage advice, which for most is a cool, dry place indoors at a partial charge. Check your manual for the exact level.
Warm-season lawn: fall checklist
Bermuda, zoysia, St. Augustine and centipede. These go dormant in winter, so fall care is about protecting them, not pushing growth.
| When | Task |
|---|---|
| August | Last nitrogen; lower summer mowing height back to normal |
| September | Soil test; potassium if needed; winter-weed pre-emergent |
| September to October | Optional ryegrass overseed for winter color |
| October to November | Keep leaves off; water if dry |
| Late fall | Second pre-emergent in some areas |
1. Stop nitrogen by the end of August
This is the most important rule on the warm-season list. UGA’s Forsyth County office says make the last nitrogen application in August, because fall feeding can delay dormancy, raise the risk of cold injury and increase spring dead spot.
Clemson says the last nitrogen should go down at least two months before your average first frost, with a light rate of 1/2 lb or less per 1,000 sq ft. NC State’s Sampson County office says no nitrogen until May of next year. Many weed-and-feed products are high in nitrogen, so Clemson advises against using them in fall unless you know what you’re doing.
2. Potassium, if a soil test says so
Potassium improves cold tolerance. Clemson suggests about 1 lb of potash per 1,000 sq ft if a soil test shows it’s low, and says lawns fed all summer with a fertilizer high in potassium probably don’t need more. Too much potassium can burn leaves and lighten color.
UGA suggests taking soil samples about 4 inches deep in September. Their ideal pH ranges: 5.5 to 6.5 for bermuda, 5.0 to 6.0 for centipede and 6.0 to 7.0 for zoysia.
3. Pre-emergent for winter weeds
Winter weeds such as annual bluegrass and henbit sprout as soil cools. UGA suggests a pre-emergent in September, or before nighttime temperatures drop below 60°F. UGA also warns against atrazine products on bermuda. NC State’s Sampson office suggests one application after Labor Day and another near Thanksgiving.
Follow the label, and skip it on any area you plan to overseed with ryegrass.
4. Mowing
UGA says keep bermuda, centipede and zoysia at 1 to 2 inches, and in August lower the blade back to normal if you raised it half an inch for summer heat. Clemson’s winterizing guide suggests raising height in late summer for more carbohydrates and deeper roots. Follow the range for your grass in how to mow a lawn, and keep mowing until the lawn goes dormant.
5. Overseed with ryegrass (optional)
If a brown winter lawn bothers you, ryegrass gives green color through winter. UGA lists 5 to 10 lb of ryegrass per 1,000 sq ft on established bermuda, mostly in fall. The trade-off: the ryegrass competes with your bermuda during spring green-up. Many people skip it for that reason.
6. Leaves and aeration
Clemson says keep leaves off warm-season lawns so the grass can keep photosynthesizing before dormancy. Shaded grass stays cold longer and stores less energy.
Don’t aerate now. Clemson recommends aerating warm-season lawns in spring after green-up, and UGA rates late spring and summer as the best time.
7. Water as needed
UGA suggests about 1 inch per week when it hasn’t rained, counting rain and irrigation, ideally in two waterings. Keep any newly laid sod moist through fall and winter.
What to skip in fall
- Nitrogen on warm-season grass after August.
- Fertilizer on frozen ground, any grass.
- Pre-emergent on newly seeded areas, unless the label allows it.
- Scalping the last mow. A little shorter is fine, very short is not.
- Leaving a thick leaf mat over winter.
Looking ahead: the next jobs are in the spring lawn care checklist, and the whole year is laid out in the lawn care calendar.
FAQ
What should I put on my lawn in the fall?
For cool-season grass, a fertilizer at about 1 lb of nitrogen per 1,000 sq ft in September, and optionally a late-fall feeding in early November. Warm-season grass should get no nitrogen after August, and potassium only if a soil test shows it's low. Follow the label.
When should I stop mowing in the fall?
When the grass stops growing. In the upper Midwest that's usually late October or early November, when daytime highs stay below about 50°F. Warm-season lawns stop when they go dormant.
Is it better to mulch or rake leaves?
Thin, dry layers can be mulched into the lawn with a mulching mower. Heavy layers should be raked, blown or bagged so they don't smother the grass. Leaves raked into beds also help overwintering insects.
When is the best time to aerate in fall?
Early September for cool-season lawns, a few days after rain when the soil is moist. Warm-season lawns should be aerated in late spring or summer instead, not in fall.
Is it too late to seed in October?
For cool-season grass in most of the north, usually yes for best results, since the window runs mid-August to mid-September. Seed sown in October often sprouts too late to establish before winter.
Should I fertilize my bermuda lawn in the fall?
No nitrogen after August. UGA says fall nitrogen can delay dormancy, raise cold injury risk and increase spring dead spot. Potassium is the exception if a soil test shows it's low.
When should I kill weeds in the fall?
Spray perennial broadleaf weeds like dandelions and creeping Charlie from late September to early November. They move sugars to their roots then, which carries the herbicide down and kills the whole plant.
Should I cut grass short for winter?
Slightly shorter for the last mow, yes, but never scalp it. Iowa State suggests lowering cool-season lawns from 3 to 3.5 inches back to 2.5 to 3 inches in mid to late September.