When to Plant Watermelon in USDA Zone 10b
June in the garden — Zone 10b
We've pulled the most time-sensitive tasks for Zone 10b this June and put them front and centre. Tackle them in order.
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Harvest watermelon as they ripen
If you can't use it all right away, check the food-preservation section of your planner.
Watermelon is a sprawling vine crop that produces sweet, juicy fruits in hot weather. Varieties range from personal-sized icebox types to 50-pound giants.
In Zone 10b, the average last spring frost is around January 1 and the first fall frost is around December 31, giving you a growing season of approximately 364 days.
Watermelon Planting Timeline — Zone 10b
Where Is USDA Zone 10b?
The map below highlights the states that contain Zone 10b. Click any state to see the Watermelon planting schedule for that location.
Watermelon Planting Calendar — Zone 10b
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 4 | Dec 4 – Dec 18 |
| Transplant Outdoors | January 8 | Jan 8 – Jan 22 |
| Direct Sow | January 1 | Jan 1 – Jan 22 |
| Harvest | March 19 | Mar 19 – May 7 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Transplant Outdoors Direct Sow |
| February | — |
| March | Harvest |
| April | Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | Start Indoors |
Free Zone 10b Planting Calendar PDF
Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 10b with start dates, transplant windows, and harvest times.
Growing Conditions
Sun
Full Sun (6-8+ hours)
💧 Water
1.5"/week · Moderate — regular watering
Days to Maturity
70–100 days
Soil pH
6 – 7.5
Zone Temperature Range
35°F to 40°F average annual minimum
Growing Season
365 days (Zone 10b average)
Planting Specifications
| Planting Depth | 1 inches |
| Plant Spacing | 30 inches apart |
| Row Spacing | 42 inches between rows |
Succession Planting Watermelon in Zone 10b
Sow every 8 weeks for continuous harvest throughout the season.
Recommended Watermelon Varieties for Zone 10b
Full-size melons that thrive with your long season
Growing Tips for Watermelon in Zone 10b
Zone 10b offers a long growing season (~365 days). You can plant Watermelon earlier and may get multiple harvests.
Watermelon needs approximately 1.5 inches of water per week during active growth. Adjust watering based on your local rainfall and soil drainage.
Start seeds indoors 3-4 weeks early or direct sow after soil is warm. Plant on mounds with plenty of space. Check ripeness by looking for a yellow ground spot and dull thump when tapped.
Companion Planting
Good Companions
Avoid Planting Near
The Gardener's Encyclopedia to Companion Planting
The pairings that make vegetables, herbs, and flowers grow better — and the ones that quietly wreck a bed.
- Proven pairings for 200+ vegetables, herbs, flowers, and fruits
- Full seed-starting + planting schedule with timing and spacing
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Saving Watermelon Seeds
Recommended for Your Garden
Reduce heat stress and sun scorch in hot climates with UV-stabilized shade cloth.
Start seeds indoors with reusable cell trays and humidity domes.
Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.
Related Plants
Watermelon in Other Zones
Watermelon by State
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
Frequently Asked Questions
When should I plant Watermelon in Zone 10b?
In Zone 10b, plan your Watermelon planting around the average last frost date of January 1. Start seeds indoors around December 4. Direct sow outdoors around January 1. Transplant seedlings around January 8.
Can Watermelon grow in Zone 10b?
Yes, Watermelon can grow well in Zone 10b, hardy in USDA zones 4a through 11b. Zone 10b has a growing season of approximately 364 days, which is sufficient for Watermelon (70-100 days to maturity).
When can I harvest Watermelon in Zone 10b?
In Zone 10b, expect to harvest Watermelon from March 19 – May 7. Watermelon takes 70-100 days from planting to harvest.
What is the last frost date for Zone 10b?
The average last spring frost in Zone 10b is around January 1, and the first fall frost is around December 31. This gives a growing season of approximately 364 days. These are 50% probability dates — actual frost dates vary year to year.
What should I plant next to Watermelon?
Good companion plants for Watermelon include Corn, Radish, Lettuce. These companions can help with pest control, pollination, and nutrient sharing.
Your Zone 10b Garden Planner — Free
A 22-page printable planner tailored to Zone 10b. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.