When to Plant Watermelon in Garfield County, WA
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.
Garfield County, Washington is in USDA Zone 6a. The average last spring frost is May 9 and the first fall frost is September 30, giving you a growing season of approximately 144 days.
At an elevation of 3,226 feet, Garfield County receives approximately 17.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°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.
Garfield County Soil Profile
Soil Type
Silt Loam
Soil pH
5.6-6.8
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 6/10 — consider drought-tolerant varieties and mulching
Watermelon Planting Timeline — Garfield County, WA
Watermelon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 4 | Apr 4 – Apr 18 |
| Transplant Outdoors | May 23 | May 23 – Jun 6 |
| Direct Sow | May 16 | May 16 – Jun 6 |
| Harvest | August 1 | Aug 1 – Sep 19 |
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 6a
Growing Season
144 days
Growing Tips for Garfield 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 Garfield County, WA?
Garfield County is in Zone 6a with an average last frost of May 9. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Garfield County, WA?
Garfield County, Washington is in USDA Hardiness Zone 6a. The average last spring frost is May 9 and first fall frost is September 30.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Garfield County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.
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