When to plant sweet corn in zone 5b
In zone 5b, where the last spring frost typically comes around May 1, sow outdoors May 1 to 15.
The zone 5b schedule for sweet corn
- Sow outdoors
- May 1 to 15
- Safest planting date (10% frost risk)
- May 16
- First harvest, roughly
- June 30 to August 23
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 sweet corn.
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
Sweet Corn are killed by frost, so if you want to be safe, plant out after the safe date rather than the typical one, or be ready to cover plants on a cold night.
Your dates for sweet corn
Set your ZIP code at the top of the page and we will work out when to plant sweet corn where you live, from the frost records of the nearest NOAA weather station. Your ZIP code is remembered on this device only.
Sweet Corn in zone 5b cities
| City | Typical last frost | Plant | Fall |
|---|---|---|---|
| Milwaukee, WI | Apr 19 | Apr 27 to May 11 | — |
| Madison, WI | May 1 | May 1 to 15 | — |
| Des Moines, IA | Apr 18 | Apr 18 to May 2 | — |
| Aurora, IL | Apr 19 | Apr 19 to May 3 | — |
| Fort Collins, CO | May 2 | May 2 to 16 | — |
| Naperville, IL | Apr 19 | Apr 19 to May 3 | — |
| Rockford, IL | Apr 24 | Apr 24 to May 8 | — |
| Elgin, IL | Apr 26 | Apr 26 to May 10 | — |
| Greeley, CO | May 2 | May 2 to 16 | — |
| Green Bay, WI | Apr 30 | Apr 30 to May 14 | — |
| Davenport, IA | Apr 19 | Apr 19 to May 3 | — |
| Longmont, CO | May 6 | May 6 to 20 | — |
How to grow sweet cornAll zonesSweet Corn in zone 5aSweet Corn in zone 6aAbout zone 5b
Sources
- How to Grow Sweet Corn in Your Garden · Utah State University Extension
- Growing Sweet Corn in a Home Garden · University of Maryland Extension
- Growing Home Garden Sweet Corn (Circular 905) · University of Georgia Cooperative Extension
- Sweet Corn (HGIC factsheet) · Clemson Cooperative Extension Home & Garden Information Center
- Florida Vegetable Gardening Guide (SP103/VH021) · University of Florida IFAS Extension
- Vegetable Planting Calendar for Maricopa County (AZ1005) · University of Arizona Cooperative Extension
- GN 154: Soil Temperature Conditions for Vegetable Seed Germination (Harrington emergence table) · UC Cooperative Extension, Sacramento County (UC ANR)
- Fall Vegetable Gardening (SPES-801) · Virginia Cooperative Extension