Lawn care calendar · from LawnzoLawn care calendar for Ohio: when to fertilize and seed
Ohio lawns are mostly cool-season grasses, which grow hardest in spring and fall. Ohio State University Extension puts feeding in April and May and again in September and October, and seeding in late August or September. The calendar and frost dates below turn that into a month-by-month plan.
Short answer
Fertilize Ohio lawns in April and May and again in September and October.
Ohio State University Extension says lawns can generally be fertilized in April and May and again in September and October, and that summer fertilizing raises the risk of turf disease. Seed or overseed in late August or September, ideally with turf-type tall fescue. Spring seeding competes with too many weeds to work well without herbicide help.
Ohio State University Extension
| Month | Cool-season lawns | Notes |
|---|---|---|
| January | Dormant | Soil test results guide fertilizer and lime decisions |
| February | Dormant; get the mower serviced and the blade sharpened | Nitrogen cannot be soil tested, so it is applied on a schedule |
| March | Test the soil; rake off debris | Lime only if a soil test calls for it; spring and fall are best |
| April | First feeding window opens | Choose little or no phosphorus unless a test asks for it |
| May | Feed if needed; mow at 2 to 4 inches, 2.5 to 4 for tall fescue | Leave clippings on the lawn to cut fertilizer needs |
| June | No fertilizer; keep mowing high | Summer feeding raises turf disease risk |
| July | Mow at the top of your grass range | Drought dormancy is normal; limit traffic on a stressed lawn |
| August | Late August: start seeding or overseeding | Starter fertilizer such as 18-25-12 goes down with new seed |
| September | Seed and feed | Ideal seeding window ends with September |
| October | Last feeding window closes | Sweep granules off paving |
| November | Dormant | Lime can go on when turf is not wilted or frost-covered |
| December | Dormant | Nothing to apply |
Dates shift with the weather; follow the signs in the text.
Which grasses grow where in Ohio
Ohio lawns are mostly Kentucky bluegrass, perennial ryegrass, fine fescues and tall fescue. The state extension recommends turf-type tall fescue for full sun and moderate shade, and a blend of two to four cultivars of one species for more resistance to disease and stress.
Its mowing table also lists zoysiagrass and common bermudagrass for Ohio lawns, so warm-season grass can be grown here, but the feeding and seeding dates in this calendar belong to cool-season turf.
Frost dates from NOAA
Dates are the NOAA 1991-2020 normals for the last spring and first fall 32 F freeze at 50% probability. At Cleveland Hopkins the average last spring frost is April 20 and the average first fall frost is November 3. At Columbus (John Glenn International Airport) the dates are April 18 and October 27. At Cincinnati (Lunken Field) they are April 16 and October 25.
Cleveland's first fall frost comes about a week after Columbus's on these averages (computed from the two dates). Ohio State also warns that spring freezes can injure young seedlings.
Spring
April and May are the first feeding window. Choose a fertilizer with little or no phosphorus unless a soil test shows a shortage, because phosphorus deficiency is rare in Ohio lawns and nutrient runoff feeds the algae blooms that hit Lake Erie. Several small feedings through the season beat one large one, which rain can wash away before the grass uses it.
If you must seed in spring, fast-germinating ryegrass is the recommended choice. A pre-emergent with mesotrione at seeding limits crabgrass, and other pre-emergents block grass seed from sprouting.
Summer
Fertilizing in summer heat increases several turf diseases, so skip it. Mow high instead. Ohio State's heights are 2 to 4 inches for Kentucky bluegrass, perennial ryegrass and fine fescues, 2.5 to 4 inches for tall fescue, 1 to 2.5 inches for zoysiagrass and 1 to 2 inches for common bermudagrass.
Taller grass shades the soil and holds moisture. Follow the one-third rule: a lawn kept at 3 inches should be cut before it reaches 4.5 inches.
Fall
Late August and September are the best seeding months, and September and October are the second feeding window. New seed benefits from a starter fertilizer, which carries much more phosphorus than regular lawn food, for example 18-25-12.
Leave clippings on the lawn through fall. Collecting them removes nearly three quarters of the nitrogen you applied. Sweep or blow any fertilizer off driveways and sidewalks so it does not wash into storm drains.
Ohio State Extension and soil testing
Ohio State University Extension publishes lawn fact sheets on Ohioline. Soil testing comes first: it shows pH, which should sit between 6.0 and 7.0 for most Ohio lawn grasses, and it shows whether phosphorus or potassium is short. Nitrogen is not tested, so it is applied on a schedule.
Its soil testing fact sheet lists labs in and near Ohio, including A&L Great Lakes Laboratories in Fort Wayne, Indiana, Calmar Soil Testing Labs in Westerville, Ohio and the Penn State Agricultural Analytical Services Laboratory.
Frequently asked questions
When should I fertilize my lawn in Ohio?
In April and May and again in September and October, when the lawn needs it. Skip summer, because feeding in heat increases several turf diseases.
When is the best time to seed grass in Ohio?
Late August or September. Turf-type tall fescue is a good choice for sun and moderate shade. Spring seeding fights too many weeds to work well without herbicide, and spring freezes can injure seedlings.
How tall should I mow my lawn in Ohio?
Aim for the upper half of the range for your grass: 2 to 4 inches for Kentucky bluegrass, perennial ryegrass and fine fescues, and 2.5 to 4 inches for tall fescue. Never remove more than a third of the blade at once.
Do I need phosphorus in my lawn fertilizer in Ohio?
Usually not. Phosphorus deficiency is rare in Ohio lawns, especially when clippings are returned. New seed is the main exception, and a soil test settles the question.
Can Lawnzo help me follow an Ohio lawn schedule?
Lawnzo, a lawn-care planner for iPhone, builds a seasonal plan from your grass, sun and irrigation, checks each task against the forecast and shows why it keeps, delays or skips a job. Its journal records products and photos.
Sources
- Ohioline, Efficient Lawn Care Practices to Help Protect Ohio's Waterways (HYG-5812)
- Ohioline, Lawn Mowing (HYG-5816)
- Ohioline, Lawn Grass Cultivar Selection (HYG-4027)
- Ohioline, Lime and the Home Lawn (HYG-4026)
- Ohioline, Soil Testing for Horticultural Needs (HYG-1132)
- Ohioline, Home, Yard and Garden topic index
- NOAA NCEI 1991-2020 normals: frost dates for Cleveland, Columbus and Cincinnati (API query)
- NOAA NCEI, U.S. Climate Normals 1991-2020 (product page)
- NOAA NCEI, station inventory (GHCN-Daily station list)
Checked on October 1, 2026.
For the rest, there is Lawnzo
Lawnzo turns the calendar into the right job on the right day.
A season plan for your grass and your hemisphere, checked against the forecast, with the reason shown when a job is moved or skipped.
- Mowing, watering, seeding, feeding, aerating and weeding
- Forecast checks with the reason shown
- A journal with products, costs and photos
Noted. Every tap tells us how many people want Lawnzo on Android.
See LawnzoMore in Lawn care calendar by state
- MichiganFall is the best time to seed a Michigan lawn, and spring crabgrass control runs by soil temperature, not the calendar.
- PennsylvaniaSeed in late summer to early fall, and feed in spring and again in late summer.
- IllinoisFertilize and seed Illinois lawns in late summer, with a lighter feeding in spring.
- CaliforniaWarm-season lawns are fed from April to September, and tall fescue in spring and fall.
- FloridaFertilize only during the growing season, and finish by late September in the north.
- GeorgiaFeed warm-season grasses from May through August, and tall fescue in February-March and October-November.
- Lawn fertilizer calculatorFree tool: Enter the numbers on the bag and your lawn size. See how many pounds of fertilizer to spread per 1,000 sq ft and in total, and how many bags you need.
