When to plant tomatoes in zone 5b
In zone 5b, where the last spring frost typically comes around May 1, start tomatoes indoors March 28 to April 11 and plant out May 23 to June 6.
The zone 5b schedule for tomatoes
- Start seeds indoors
- March 28 to April 11
- Plant out
- May 23 to June 6
- Soil warm enough (60°F), about
- May 23
- First harvest, roughly
- July 14 to September 4
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 tomatoes.
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
Tomatoes 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 tomatoes
Set your ZIP code at the top of the page and we will work out when to plant tomatoes where you live, from the frost records of the nearest NOAA weather station. Your ZIP code is remembered on this device only.
Tomatoes in zone 5b cities
| City | Typical last frost | Start indoors | Plant out |
|---|---|---|---|
| Milwaukee, WI | Apr 19 | Mar 30 to Apr 13 | May 25 to Jun 8 |
| Madison, WI | May 1 | Mar 27 to Apr 10 | May 22 to Jun 5 |
| Des Moines, IA | Apr 18 | Mar 15 to 29 | May 10 to 24 |
| Aurora, IL | Apr 19 | Mar 20 to Apr 3 | May 15 to 29 |
| Fort Collins, CO | May 2 | Mar 28 to Apr 11 | May 23 to Jun 6 |
| Naperville, IL | Apr 19 | Mar 20 to Apr 3 | May 15 to 29 |
| Rockford, IL | Apr 24 | Mar 20 to Apr 3 | May 15 to 29 |
| Elgin, IL | Apr 26 | Mar 23 to Apr 6 | May 18 to Jun 1 |
| Greeley, CO | May 2 | Mar 23 to Apr 6 | May 18 to Jun 1 |
| Green Bay, WI | Apr 30 | Mar 31 to Apr 14 | May 26 to Jun 9 |
| Davenport, IA | Apr 19 | Mar 17 to 31 | May 12 to 26 |
| Longmont, CO | May 6 | Mar 30 to Apr 13 | May 25 to Jun 8 |
How to grow tomatoesAll zonesTomatoes in zone 5aTomatoes in zone 6aAbout zone 5b
Sources
- Tomato (HGIC 1323) · Clemson Cooperative Extension, Home & Garden Information Center
- How to Grow Tomatoes in Your Garden · Utah State University Extension
- Easy Gardening: Tomatoes (EHT-043) · Texas A&M AgriLife Extension Service
- Florida Vegetable Gardening Guide (SP 103/VH021) · UF/IFAS Extension
- Vegetable Planting Calendar for Maricopa County (AZ1005) · University of Arizona Cooperative Extension
- Soil Temperature Conditions for Vegetable Seed Germination (Garden Notes GN 154) · UC Cooperative Extension Sacramento County (UC ANR)
- Solanum lycopersicum (Tomato) · NC State Extension Gardener Plant Toolbox
- Vegetable Gardening in Containers (E-545) · Texas A&M AgriLife Extension Service
- Types of Containers for Growing Vegetables · University of Maryland Extension