Lawn care calendar for Wisconsin.
The University of Wisconsin calendar names early September as the key feeding for every lawn and warns against feeding in mid-fall.
Get dates for my ZIP →By LawnYear editorial team · Published · Updated Windows are read from the extension publications listed under Sources; the dates are approximate.
Short answer for Wisconsin
In Wisconsin, for Kentucky bluegrass, tall fescue, perennial ryegrass and fine fescue, seed Aug 20 to Sep 10 and Apr 20 to May 10; fertilize Sep 1 to Sep 15 and May 20 to Jun 10, per University of Wisconsin-Madison Division of Extension (2022 and 2025).
The same calendar gives watering Jun 1 to Aug 31.
Approximate dates for your state. Check with your local cooperative extension office before you act.
Windows by grass and task
| Grass | Seed | Fertilize | Water | Source |
|---|---|---|---|---|
| Kentucky bluegrass | Aug 20 to Sep 10Apr 20 to May 10 | Sep 1 to Sep 15May 20 to Jun 10 | Jun 1 to Aug 31 | University of Wisconsin-Madison Division of Extension, 2025University of Wisconsin-Madison Division of Extension, 2022 |
| Tall fescue | Aug 20 to Sep 10Apr 20 to May 10 | Sep 1 to Sep 15May 20 to Jun 10 | Jun 1 to Aug 31 | University of Wisconsin-Madison Division of Extension, 2025University of Wisconsin-Madison Division of Extension, 2022 |
| Perennial ryegrass | Aug 20 to Sep 10Apr 20 to May 10 | Sep 1 to Sep 15May 20 to Jun 10 | Jun 1 to Aug 31 | University of Wisconsin-Madison Division of Extension, 2025University of Wisconsin-Madison Division of Extension, 2022 |
| Fine fescue | Aug 20 to Sep 10Apr 20 to May 10 | Sep 1 to Sep 15May 20 to Jun 10 | Jun 1 to Aug 31 | University of Wisconsin-Madison Division of Extension, 2025University of Wisconsin-Madison Division of Extension, 2022 |
Calendar by grass
Grasses the source covers with one shared calendar are shown together. Open a group for each task, its note and its source. Want dates for your ZIP code? Use the lawn schedule by ZIP tool.
Kentucky bluegrass, tall fescue, perennial ryegrass and fine fescue
5 tasks
Kentucky bluegrass, tall fescue, perennial ryegrass and fine fescue in Wisconsin
Seed
Aug 20 – Sep 10
Seed, sod or renovate in late August to early September (shown as August 20 to September 10, this site's reading of the season words), after preparing the soil 4 to 6 in deep. Early fall is the better choice.
Kentucky bluegrass, tall fescue, perennial ryegrass and fine fescue in Wisconsin
Seed
Apr 20 – May 10
Spring seeding or overseeding in late April to early May (this site's reading) works only if seedlings can establish before hot weather; the calendar prefers early fall.
Kentucky bluegrass, tall fescue, perennial ryegrass and fine fescue in Wisconsin
Fertilize
Sep 1 – Sep 15
Early fall, September 1 to 15, is the key nitrogen time for all lawns: about 1 lb per 1,000 sq ft of controlled-release nitrogen. Avoid mid-fall nitrogen. A3435 adds that no application should exceed 1 lb of nitrogen per 1,000 sq ft.
Kentucky bluegrass, tall fescue, perennial ryegrass and fine fescue in Wisconsin
Fertilize
May 20 – Jun 10
Medium and high maintenance lawns get nitrogen in late May to early June, around Memorial Day (this site's reading): 1 lb per 1,000 sq ft in full sun and 1/2 lb in shade. The calendar says to wait until the second mowing in spring.
Kentucky bluegrass, tall fescue, perennial ryegrass and fine fescue in Wisconsin
Water
Jun 1 – Aug 31
About 1 inch of water a week in summer keeps a lawn green and growing, applied early in the day, deeply and evenly; decide before drought whether to irrigate or let the lawn go dormant. Months are this site's reading of 'summer'.
Kentucky bluegrass in other statesTall fescue in other statesPerennial ryegrass in other statesFine fescue in other states
Two University of Wisconsin sources for cool-season lawns
The Wisconsin Lawn Care Calendar, by Bruce Spangenberg and reviewed by Doug Soldat, covers Kentucky bluegrass, perennial ryegrass, tall fescue and fine fescues by season. A3435, Lawn Maintenance, adds a fertilization table by maintenance level. This site applies both to the four cool-season grasses.
The most important feeding is September 1 to 15
Early fall is the key nitrogen time for all lawns, about 1 lb of controlled-release nitrogen per 1,000 sq ft, and A3435 says it is the most important feeding for low and medium maintenance lawns. The calendar says to avoid mid-fall nitrogen, while A3435's holiday schedule lists a feeding in early October for medium and high maintenance lawns, so the two do not fully agree.
Late summer seeding, with spring as a second try
Seeding, sodding and renovation belong in late August to early September, after preparing the soil 4 to 6 in deep. Spring seeding in late April to early May is possible if seedlings can establish before the heat, but the calendar names early fall as the better choice. It also lists dormant seeding just before snowfall, and does not recommend it in most cases.
A single rule for mowing, water and spring nitrogen
The calendar says to mow at about 3 in for the entire season and to wait for the second mowing before the spring feeding, and to give about an inch of water a week in summer. A3435 puts the normal rate at about 1 lb per application and 3 lb a year, and says never to exceed 1 lb in one application. Neither document gives a month range for mowing, so the calendar shows only watering for summer.
Sources
The dates and figures on this page come from these publications.
- [1]University of Wisconsin-Madison Division of Extension ↗ (opens in a new tab)Wisconsin Lawn Care Calendar (2025); spring, summer and fall practices for cool-season grasses.Publication year 2025 · Read 2026-10-30
- [2]University of Wisconsin-Madison Division of Extension ↗ (opens in a new tab)A3435, Lawn Maintenance (2022); fertilization periods and rates by maintenance level, and a limit of 1 lb of nitrogen per application.Publication year 2022 · Read 2026-10-30