When to Plant Watermelon in Nez Perce County, ID
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.
Nez Perce County, Idaho is in USDA Zone 6b. The average last spring frost is May 12 and the first fall frost is September 26, giving you a growing season of approximately 137 days.
At an elevation of 4,819 feet, Nez Perce County receives approximately 16.7 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Watermelon during the growing season. With low rainfall, drip irrigation is essential for growing Watermelon successfully. Mulch heavily to conserve soil moisture.
Nez Perce County Soil Profile
Soil Type
Loam
Soil pH
6.6-8
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
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Watermelon Planting Timeline — Nez Perce County, ID
Watermelon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 7 | Apr 7 – Apr 21 |
| Transplant Outdoors | May 26 | May 26 – Jun 9 |
| Direct Sow | May 19 | May 19 – Jun 9 |
| Harvest | August 4 | Aug 4 – Sep 22 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | — |
| 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 6b
Growing Season
137 days
Growing Tips for Nez Perce 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 Nez Perce County, ID?
Nez Perce County is in Zone 6b with an average last frost of May 12. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Nez Perce County, ID?
Nez Perce County, Idaho is in USDA Hardiness Zone 6b. The average last spring frost is May 12 and first fall frost is September 26.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Nez Perce County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.
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