When to plant watermelons in zone 6b
In zone 6b, where the last spring frost typically comes around April 23, start watermelons indoors April 7 to 21 and plant out May 12 to 26.
The zone 6b schedule for watermelons
- Start seeds indoors
- April 7 to 21
- Plant out
- May 12 to 26
- Sow outdoors
- May 12 to 26
- Soil warm enough (60°F), about
- May 12
- First harvest, roughly
- July 11 to August 24
From the median frost dates of the NOAA stations assigned to the 4,514 ZIP codes in zone 6b, and the timing recommended by Cooperative Extension guides for watermelons.
Frost risk in zone 6b
Zones are based on winter cold, not on frost dates, so the last spring frost varies a lot within a zone. Across zone 6b, the typical last frost ranges from about April 10 in the earliest tenth of ZIP codes to May 6 in the latest tenth, and the first fall frost from October 9 to October 29. For a typical place in the zone:
- April 8Risky: a later frost happens in 9 years out of 10
- April 23Typical: frost after this date in half of years
- May 9Safe: a later frost only 1 year in 10
Watermelons 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 watermelons
Set your ZIP code at the top of the page and we will work out when to plant watermelons where you live, from the frost records of the nearest NOAA weather station. Your ZIP code is remembered on this device only.
Watermelons in zone 6b cities
| City | Typical last frost | Start indoors | Plant out |
|---|---|---|---|
| Columbus, OH | Apr 18 | Apr 1 to 15 | May 6 to 20 |
| Boston, MA | Apr 4 | Apr 17 to May 1 | May 22 to Jun 5 |
| Detroit, MI | Apr 21 | Apr 12 to 26 | May 17 to 31 |
| Kansas City, MO | Apr 4 | Mar 23 to Apr 6 | Apr 27 to May 11 |
| Cleveland, OH | Apr 8 | Apr 10 to 24 | May 15 to 29 |
| Cincinnati, OH | Apr 16 | Mar 28 to Apr 11 | May 2 to 16 |
| Pittsburgh, PA | Apr 24 | Apr 6 to 20 | May 11 to 25 |
| Buffalo, NY | Apr 24 | Apr 18 to May 2 | May 23 to Jun 6 |
| Toledo, OH | Apr 20 | Apr 8 to 22 | May 13 to 27 |
| Boise City, ID | Apr 24 | Apr 11 to 25 | May 16 to 30 |
| Spokane, WA | Apr 26 | Apr 25 to May 9 | May 30 to Jun 13 |
| Rochester, NY | Apr 24 | Apr 15 to 29 | May 20 to Jun 3 |
How to grow watermelonsAll zonesWatermelons in zone 6aWatermelons in zone 7aAbout zone 6b
Sources
- Growing Watermelon in the Home Garden · Iowa State University Extension and Outreach
- How to Grow Watermelon in Your Garden · Utah State University Extension
- Watermelon (HGIC factsheet) · Clemson Cooperative Extension Home & Garden Information Center
- Citrullus lanatus (Watermelon) · NC State Extension Gardener Plant Toolbox
- Florida Vegetable Gardening Guide (SP103/VH021) · University of Florida IFAS Extension
- Vegetable Planting Calendar for Maricopa County (AZ1005) · University of Arizona Cooperative Extension