Question 1

When should I plant watermelon in ZIP 46204?

Accepted Answer

In ZIP 46204, the main watermelon target is around May 9, based on the representative Indianapolis frost station and USDA zone 6b.

Question 2

When should I start watermelon seeds indoors in 46204?

Accepted Answer

Start watermelon seeds indoors in ZIP 46204 around Apr 4, about 21 days before the Apr 25 last-frost estimate.

Question 3

When is the last frost in Indianapolis?

Accepted Answer

Indianapolis (ZIP 46204) has an average last spring frost around Apr 25, based on the representative Indianapolis frost station.

Question 4

When is the first frost in Indianapolis?

Accepted Answer

Indianapolis (ZIP 46204) has an average first fall frost around Oct 15, leaving about 173 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 4, 2026	Start seeds under lights or in a bright indoor seed-starting space.
Transplant Outdoors	May 9, 2026	Move hardened-off seedlings outside after the frost-risk window.
Direct Sow	May 9, 2026	Sow seed outside when the crop and soil can handle the window.

Start watermelon seeds indoors around Apr 4

Watermelon dates for Indianapolis, IN