Watermelon illustration 🍉

🍉 Growing Watermelon in Zone 10a

Zone 10a has a year-round growing season. Watermelon can be planted almost any time with proper planning. Last frost: Feb 20. First frost: Dec 1.

Planting Calendar

Indoor
Outdoor
Harvest
Jan 23Dec 1

Season: Feb 20 – Dec 1 (284 days)

Zone10a
Last FrostFeb 20
First FrostDec 1
Season Length284 days
Days to Harvest90
SunFull Sun
Frost ToleranceNone
Spacing1/sqft (12" apart)

When to Plant Watermelon in Zone 10a

Start Seeds Indoors: Jan 23

Start Watermelon seeds indoors around Jan 23 (4 weeks before last frost). Optimal germination temperature: 85°F. Germinates in 4–12 days.

Transplant Outdoors: Mar 6

Transplant Watermelon seedlings outdoors after Mar 6. Wait until soil temperature reaches 70°F. Space plants at 1/sqft (12" apart). Harden off plants for a week before moving outside.

Harvest: May 20

First harvest approximately May 20 (~75 days from transplant). Continue harvesting until first frost (Dec 1).

Companion Planting

✅ Corn✅ Nasturtiums✅ Marigolds✅ Radishes
❌ Potatoes❌ Cucumbers

Plan Your Watermelon Garden

Track Watermelon from seed to harvest with personalized frost dates, watering recommendations, and companion planting visualization.

Start Free Watermelon Growing Guide