When should I plant watermelon in ZIP 74103?

In ZIP 74103, the main watermelon target is around Apr 19, based on the representative Tulsa frost station and USDA zone 7b.

When should I start watermelon seeds indoors in 74103?

Start watermelon seeds indoors in ZIP 74103 around Mar 15, about 21 days before the Apr 5 last-frost estimate.

Is this a guaranteed planting date?

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

ZIP 74103 planting calendar

When to plant watermelon in Tulsa, OK - Zone 7b

Q: When is the first frost in Tulsa?

Tulsa (ZIP 74103) has an average first fall frost around Oct 30, leaving about 208 frost-free days.

In ZIP 74103, plant watermelon around Apr 19; this uses the Tulsa frost station, USDA zone 7b, and watermelon timing rules.

Your Tulsa calendar has a 208-day estimated frost-free season. This estimate uses the representative Tulsa frost station, USDA zone 7b, and watermelon timing rules.

Source: tulsa-intl frost station, USDA zone 7b, last updated 2026-06-28. Verify locally before planting high-value crops because microclimates, current weather, and yard exposure can move the safe date.

Reviewed by GrowZone Editorial. Calculated from the tulsa-intl frost station and USDA zone 7b, last updated 2026-06-28.

In the Tulsa area, watermelon timing follows the Tulsa frost window, so the local ZIP date can differ from a broad zone-only calendar.

USDA zone 7b Tulsa frost station Oklahoma State University Extension Updated 2026-06-28

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Answer first

When to start watermelon seeds indoors in Tulsa

In ZIP 74103, start watermelon seeds indoors around Mar 15, about 21 days before the Apr 5 last-frost estimate.

Start watermelon seeds indoors in Tulsa around Mar 15, about 21 days before the Apr 5 last-frost estimate.

Seed starting schedule

Watermelon dates for Tulsa, OK

Step	Date	How to use it
Start Indoors	March 15, 2026	Start seeds under lights or in a bright indoor seed-starting space.
Transplant Outdoors	April 19, 2026	Move hardened-off seedlings outside after the frost-risk window.
Direct Sow	April 19, 2026	Sow seed outside when the crop and soil can handle the window.

Last frost

When is the last frost in Tulsa?

Tulsa (ZIP 74103) has an average last spring frost around Apr 5.

First frost

When is the first frost in Tulsa?

The average first fall frost is around Oct 30, giving about 208 frost-free days.

Season map

Watermelon windows by month

JanFebMarAprMayJunJulAugSepOctNovDec

Start indoors

Mar 15

Direct sow

Apr 19

Transplant

Apr 19

Harvest

Jul 18

Frost watch

Aug 1

Reminder workflow

Every date has a next action

Start watermelon indoorsMar 15

Last frost windowApr 5

Direct sow watermelonApr 19

Transplant watermelonApr 19

First watermelon harvest windowJul 18

Last watermelon sowing targetAug 1

Signal	Value	Why it matters
Last frost estimate	April 5, 2026	Warm-season transplant risk starts falling after this window.
First frost estimate	October 30, 2026	Fall planting counts backward from this date.
Season length	208 days	Longer seasons can support succession crops.
Spacing	36-60 in	Airflow and root space affect yield.
Soil temperature	70 F+	Seeds and transplants stall in cold soil.

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Local data

Why this date changes by ZIP

Tulsa frost history and USDA zone 7b shift the safe planting window. GrowZone uses a local representative station instead of one national rule.

Oklahoma State University Extension is the kind of local source to verify against when a crop is expensive, weather is unusual, or your yard has a cold pocket.

Crop note

Watermelon timing notes

Wait for warm soil; watermelon stalls when nights stay cool. Watermelon prefers full sun, 36-60 in spacing, and soil near 70 F+.

For fall, count backward from Oct 30. A conservative last sowing target is around Aug 1.