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When to Plant Watermelon in Bristol County, RI

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.

Bristol County, Rhode Island is in USDA Zone 6b. The average last spring frost is April 26 and the first fall frost is October 17, giving you a growing season of approximately 174 days.

At an elevation of 335 feet, Bristol County receives approximately 41.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Watermelon during the growing season.

Bristol County, RI (Zone 6b) Moderate season
174 days
Last Spring Frost April 26
174 growing days
First Fall Frost October 17

Bristol County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (42 days to spare)
Start indoors: Mar 15 Transplant: May 3 🍅 Harvest: Jul 12 – Aug 30
Recommended (50%) ✓ Fits season (41 days to spare)
Start indoors: Mar 22 Transplant: May 10 🍅 Harvest: Jul 19 – Sep 6
Safe Start (90%) ✓ Fits season (38 days to spare)
Start indoors: Apr 9 Transplant: May 28 🍅 Harvest: Aug 6 – Sep 24

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Watermelon needs ~1,296 GDD — county provides 2,653 GDD Excellent fit

Watermelon Planting Timeline โ€” Bristol County, RI

Watermelon Planting Calendar

Activity When Date Range
Start Indoors March 22 Mar 22 โ€“ Apr 5
Transplant Outdoors May 10 May 10 โ€“ May 24
Direct Sow May 3 May 3 โ€“ May 24
Harvest July 19 Jul 19 โ€“ Sep 6

Plant 1" deep ยท 30" apart ยท Rows 42" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Start Indoors
May Transplant Outdoors Direct Sow
June โ€”
July Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

70โ€“100 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 6b

Growing Season

174 days

Growing Tips for Bristol County

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

  • Potatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Watermelon in Bristol County, RI?

Bristol County is in Zone 6b with an average last frost of April 26. Plan your Watermelon planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Bristol County, RI?

Bristol County, Rhode Island is in USDA Hardiness Zone 6b. The average last spring frost is April 26 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Bristol County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Bristol County, RI. Local conditions may vary. Last updated: April 2026.