When to plant grass seed in zone 5b
In zone 5b, where the last spring frost typically comes around May 1, sow outdoors March 20 to April 3. For a fall crop, plant August 29 to September 12.
The zone 5b schedule for grass seed
- Sow outdoors
- March 20 to April 3
- Plant for a fall crop
- August 29 to September 12
From the median frost dates of the NOAA stations assigned to the 2,546 ZIP codes in zone 5b, and the timing recommended by Cooperative Extension guides for grass seed.
Dates before the last frost assume the soil has thawed and is dry enough to work: a squeezed handful crumbles instead of sticking. After a late or wet spring, wait for that even if the date has passed.
Frost risk in zone 5b
Zones are based on winter cold, not on frost dates, so the last spring frost varies a lot within a zone. Across zone 5b, the typical last frost ranges from about April 21 in the earliest tenth of ZIP codes to May 18 in the latest tenth, and the first fall frost from September 30 to October 19. For a typical place in the zone:
- April 18Risky: a later frost happens in 9 years out of 10
- May 1Typical: frost after this date in half of years
- May 16Safe: a later frost only 1 year in 10
Your dates for grass seed
Set your ZIP code at the top of the page and we will work out when to plant grass seed where you live, from the frost records of the nearest NOAA weather station. Your ZIP code is remembered on this device only.
Grass Seed in zone 5b cities
| City | Typical last frost | Plant | Fall |
|---|---|---|---|
| Milwaukee, WI | Apr 19 | Mar 8 to 22 | Sep 17 to Oct 1 |
| Madison, WI | May 1 | Mar 20 to Apr 3 | Aug 29 to Sep 12 |
| Des Moines, IA | Apr 18 | Mar 7 to 21 | Sep 8 to 22 |
| Aurora, IL | Apr 19 | Mar 8 to 22 | Sep 11 to 25 |
| Fort Collins, CO | May 2 | Mar 21 to Apr 4 | Aug 26 to Sep 9 |
| Naperville, IL | Apr 19 | Mar 8 to 22 | Sep 11 to 25 |
| Rockford, IL | Apr 24 | Mar 13 to 27 | Sep 5 to 19 |
| Elgin, IL | Apr 26 | Mar 15 to 29 | Sep 6 to 20 |
| Greeley, CO | May 2 | Mar 21 to Apr 4 | Aug 27 to Sep 10 |
| Green Bay, WI | Apr 30 | Mar 19 to Apr 2 | Aug 28 to Sep 11 |
| Davenport, IA | Apr 19 | Mar 8 to 22 | Sep 10 to 24 |
| Longmont, CO | May 6 | Mar 25 to Apr 8 | Aug 24 to Sep 7 |
How to grow grass seedAll zonesGrass Seed in zone 5aGrass Seed in zone 6aAbout zone 5b
Sources
- Lawn Establishment (HGIC 1203) · Clemson Cooperative Extension Home & Garden Information Center
- Starting a New Lawn · University of Maryland Extension
- AGR-50 Lawn Establishment in Kentucky · University of Kentucky Cooperative Extension Service
- Lawn Establishment · Penn State Extension
- AY-20 Seeding a Turf Area in the Spring · Purdue University Cooperative Extension Service
- Choose the right grass seed for a thriving lawn · University of Illinois Extension
- Northern Utah Turfgrass Management Calendar · Utah State University Extension
- Time for Fall Lawn Seeding · University of Nebraska-Lincoln Extension (Lancaster County)
- Spring/Summer Lawn Care (Crop and Soil Environmental News, March 2005) · Virginia Cooperative Extension / Virginia Tech
- Planting Summer Grass · NC State Extension, Pender County
- Grass seed germination rates · UC Statewide IPM Program, University of California ANR
- Turfgrass Species (Pest Management Guidelines) · UC Statewide IPM Program, University of California ANR
- ENH14 Overseeding Florida Lawns for Winter Color (2007 revision, archival) · University of Florida IFAS Extension (EDIS)
- AZ1683 Overseeding Winter Grasses into Bermudagrass Turf · University of Arizona Cooperative Extension
- Bermudagrass · K-State Research and Extension, Ford County
- Chapter 10: Turfgrass Management in Tennessee (Master Gardener Handbook) · University of Tennessee Extension
- Chapter 11: Lawns (Virginia Cooperative Extension Master Gardener Handbook) · Virginia Cooperative Extension / Virginia Tech