When to Plant Watermelon in Ontario County, NY
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.
Ontario County, New York is in USDA Zone 5b. The average last spring frost is April 29 and the first fall frost is October 20, giving you a growing season of approximately 174 days.
At an elevation of 33 feet, Ontario County receives approximately 50 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Watermelon to ensure they mature before fall.
Ontario County Soil Profile
Soil Type
Silt Loam
Soil pH
4.9-6.6
Drainage
Well Drained
Plant Planting Risk Windows
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
Watermelon Planting Timeline — Ontario County, NY
Watermelon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 25 | Mar 25 – Apr 8 |
| Transplant Outdoors | May 13 | May 13 – May 27 |
| Direct Sow | May 6 | May 6 – May 27 |
| Harvest | July 22 | Jul 22 – Sep 9 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
70–100 days
Soil pH
6 – 7.5
USDA Zone
Zone 5b
Growing Season
174 days
Growing Tips for Ontario 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
Level Up Your Garden
Watermelon in Other Locations
Frequently Asked Questions
When should I plant Watermelon in Ontario County, NY?
Ontario County is in Zone 5b with an average last frost of April 29. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Ontario County, NY?
Ontario County, New York is in USDA Hardiness Zone 5b. The average last spring frost is April 29 and first fall frost is October 20.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Ontario County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
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