Question 1

When should I plant watermelon in ZIP 43215?

Accepted Answer

In ZIP 43215, the main watermelon target is around May 14, based on the representative Columbus frost station and USDA zone 6b.

Question 2

When should I start watermelon seeds indoors in 43215?

Accepted Answer

Start watermelon seeds indoors in ZIP 43215 around Apr 9, about 21 days before the Apr 30 last-frost estimate.

Question 3

When is the last frost in Columbus?

Accepted Answer

Columbus (ZIP 43215) has an average last spring frost around Apr 30, based on the representative Columbus frost station.

Question 4

When is the first frost in Columbus?

Accepted Answer

Columbus (ZIP 43215) has an average first fall frost around Oct 15, leaving about 168 frost-free days.

Question 5

Is this a guaranteed planting date?

Accepted Answer

No. GrowZone uses frost-date estimates, hardiness zones, and crop timing rules for planning. Local microclimates and current weather can shift the right date.

Step	Date	How to use it
Start Indoors	April 9, 2026	Start seeds under lights or in a bright indoor seed-starting space.
Transplant Outdoors	May 14, 2026	Move hardened-off seedlings outside after the frost-risk window.
Direct Sow	May 14, 2026	Sow seed outside when the crop and soil can handle the window.

Start watermelon seeds indoors around Apr 9

Watermelon dates for Columbus, OH