When to Plant Leeks in Mesa County, CO
Leeks are a mild, sweet allium that produces long white shanks. They are more refined than onions and are a key ingredient in soups, stews, and gratins.
Mesa County, Colorado is in USDA Zone 6b. The average last spring frost is May 1 and the first fall frost is October 9, giving you a growing season of approximately 161 days.
At an elevation of 6,091 feet, Mesa County receives approximately 23.3 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Leeks during the growing season.
Mesa County Soil Profile
Soil Type
Loam
Soil pH
6.7-8.1
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
Leeks Planting Timeline — Mesa County, CO
Leeks Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 27 | Mar 27 – Apr 10 |
| Transplant Outdoors | May 1 | May 1 – May 15 |
| Direct Sow | April 17 | Apr 17 – May 8 |
| Fall Sowing | July 31 | Jul 31 – Aug 14 |
| Harvest | July 31 | Jul 31 – Oct 16 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Fall Sowing Harvest |
| August | Fall Sowing Harvest |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
90–150 days
Soil pH
6 – 7
USDA Zone
Zone 6b
Growing Season
161 days
Growing Tips for Mesa County
Start seeds indoors 10-12 weeks before last frost. Transplant into trenches and hill soil around stems as they grow to increase the white portion. Harvest as needed.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Leeks in Other Locations
Frequently Asked Questions
When should I plant Leeks in Mesa County, CO?
Mesa County is in Zone 6b with an average last frost of May 1. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.
What planting zone is Mesa County, CO?
Mesa County, Colorado is in USDA Hardiness Zone 6b. The average last spring frost is May 1 and first fall frost is October 9.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Mesa County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.
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