When to plant zucchini in zone 5b
In zone 5b, where the last spring frost typically comes around May 1, start zucchini indoors April 25 to May 9 and plant out May 23 to June 6.
The zone 5b schedule for zucchini
- Start seeds indoors
- April 25 to May 9
- Plant out
- May 23 to June 6
- Sow outdoors
- May 23 to June 6
- Soil warm enough (60°F), about
- May 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 zucchini.
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
Zucchini 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 zucchini
Set your ZIP code at the top of the page and we will work out when to plant zucchini where you live, from the frost records of the nearest NOAA weather station. Your ZIP code is remembered on this device only.
Zucchini in zone 5b cities
| City | Typical last frost | Start indoors | Plant out |
|---|---|---|---|
| Milwaukee, WI | Apr 19 | Apr 27 to May 11 | May 25 to Jun 8 |
| Madison, WI | May 1 | Apr 24 to May 8 | May 22 to Jun 5 |
| Des Moines, IA | Apr 18 | Apr 12 to 26 | May 10 to 24 |
| Aurora, IL | Apr 19 | Apr 17 to May 1 | May 15 to 29 |
| Fort Collins, CO | May 2 | Apr 25 to May 9 | May 23 to Jun 6 |
| Naperville, IL | Apr 19 | Apr 17 to May 1 | May 15 to 29 |
| Rockford, IL | Apr 24 | Apr 17 to May 1 | May 15 to 29 |
| Elgin, IL | Apr 26 | Apr 20 to May 4 | May 18 to Jun 1 |
| Greeley, CO | May 2 | Apr 20 to May 4 | May 18 to Jun 1 |
| Green Bay, WI | Apr 30 | Apr 28 to May 12 | May 26 to Jun 9 |
| Davenport, IA | Apr 19 | Apr 14 to 28 | May 12 to 26 |
| Longmont, CO | May 6 | Apr 27 to May 11 | May 25 to Jun 8 |
How to grow zucchiniAll zonesZucchini in zone 5aZucchini in zone 6aAbout zone 5b
Sources
- Summer Squash (HGIC factsheet) · Clemson Cooperative Extension Home & Garden Information Center
- How to Grow Summer and Winter Squash in Your Garden · Utah State University Extension
- Growing Squash in Iowa · Iowa State University Extension and Outreach
- Summer Squash (Mid-Atlantic Commercial Vegetable Production Recommendations, section F) · University of Maryland Extension
- Vegetable Planting Guide (CMG GardenNotes #720) · Colorado State University Extension
- Cucumbers, Pumpkins, Squash, and Melons (Fact Sheet 7.609) · Colorado State University Extension
- Fall Vegetable Gardening (G1343) · University of Nebraska-Lincoln Extension
- Vegetable Gardening in Containers · Texas A&M AgriLife Extension
- Florida Vegetable Gardening Guide (VH021), Table 1 · University of Florida IFAS Extension (EDIS)
- Vegetable Planting Calendar for Maricopa County (AZ1005) · University of Arizona Cooperative Extension