GrowZone

Crop by USDA zone

When to plant watermelon in zone 6b

In USDA zone 6b, plant watermelon around May 14, after the representative last frost near Apr 30. Start seeds indoors around Apr 9.

This page summarizes the supported ZIPs in zone 6b. Your exact city can move earlier or later, so use the ZIP lookup for the frost-station-specific answer.

Get exact watermelon dates by ZIP code.

Seed starting schedule

Watermelon dates for Columbus, OH

StepDateHow to use it
Start IndoorsApril 9, 2026Start seeds under lights or in a bright indoor seed-starting space.
Transplant OutdoorsMay 14, 2026Move hardened-off seedlings outside after the frost-risk window.
Direct SowMay 14, 2026Sow seed outside when the crop and soil can handle the window.
Columbus, OH · Zone 6b Watermelon May 14 Open ZIP-specific answer · last frost Apr 30 Cleveland, OH · Zone 6b Watermelon May 19 Open ZIP-specific answer · last frost May 5 Indianapolis, IN · Zone 6b Watermelon May 9 Open ZIP-specific answer · last frost Apr 25 Detroit, MI · Zone 6b Watermelon May 19 Open ZIP-specific answer · last frost May 5 Kansas City, MO · Zone 6b Watermelon Apr 29 Open ZIP-specific answer · last frost Apr 15