When to plant watermelon in USDA Zone 9b

Plan your watermelon planting around local frost risk and soil temperature, then work backward from the harvest week your buyers need. The calendar below is a starting point, not a field-level weather forecast.

Orlando, Tampa, San Antonio, southern LA coast. Average last spring frost February 5, first fall frost December 15 — a 313-day frost-free season.

Zone fit: excellent
Watermelon is well suited to Zone 9b. Standard planting dates work with minor adjustments for microclimates.

Key dates

Start seeds indoors
January 8 – January 22
Direct-seed or transplant outdoors
February 19 – March 12
Expected first harvest
May 22 – June 19

Windows are calculated from your zone's average frost dates. Adjust ±1 week for microclimates, elevation, and your own frost records.

Spacing and soil

Plant spacing
36″
Row spacing
96″
Seed depth
1″
Soil temperature
75–95°F
Frost tolerance
tender
Days to harvest
85 days

Grower notes for Zone 9b

Ripeness cue: tendril nearest the fruit turns brown and the ground spot yellows. Do not go by thumping alone.

Plant near: corn, radish

Keep away from: potatoes

Other cucurbits for Zone 9b

Same crop, other zones

Track your own plantings

BAU Farm Intelligence turns these windows into per-field tasks — indoor seed-start reminders, transplant dates, harvest projections — using your farm's actual frost history.