When to Plant Watermelon in Garfield County, CO
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, Colorado is in USDA Zone 5b. The average last spring frost is May 25 and the first fall frost is September 21, giving you a growing season of approximately 119 days.
At an elevation of 7,997 feet, Garfield County receives approximately 21.3 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Watermelon to ensure they mature before fall.
Garfield County Soil Profile
Soil Type
Loam
Soil pH
6.5-7.9
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, CO
Watermelon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 20 | Apr 20 – May 4 |
| Transplant Outdoors | June 8 | Jun 8 – Jun 22 |
| Direct Sow | June 1 | Jun 1 – Jun 22 |
| Harvest | August 17 | Aug 17 – Oct 5 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Start Indoors |
| June | Transplant Outdoors Direct Sow |
| July | — |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| 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
119 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, CO?
Garfield County is in Zone 5b with an average last frost of May 25. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Garfield County, CO?
Garfield County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 25 and first fall frost is September 21.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Garfield County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
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