Question 1

When should I plant watermelon in ZIP 85701?

Accepted Answer

In ZIP 85701, the main watermelon target is around Mar 1, based on the representative Tucson frost station and USDA zone 9b.

Question 2

When should I start watermelon seeds indoors in 85701?

Accepted Answer

Start watermelon seeds indoors in ZIP 85701 around Jan 25, about 21 days before the Feb 15 last-frost estimate.

Question 3

When is the last frost in Tucson?

Accepted Answer

Tucson (ZIP 85701) has an average last spring frost around Feb 15, based on the representative Tucson frost station.

Question 4

When is the first frost in Tucson?

Accepted Answer

Tucson (ZIP 85701) has an average first fall frost around Dec 5, leaving about 293 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	January 25, 2026	Start seeds under lights or in a bright indoor seed-starting space.
Transplant Outdoors	March 1, 2026	Move hardened-off seedlings outside after the frost-risk window.
Direct Sow	March 1, 2026	Sow seed outside when the crop and soil can handle the window.

Start watermelon seeds indoors around Jan 25

Watermelon dates for Tucson, AZ