When to plant Leeks in Mineral County, CO
Mineral County sits in USDA Zone 5a. Plant Leeks between May 27 (after last frost on June 10) and June 17. A second sowing from July 5 to July 19 extends the harvest into fall.
When to Plant Leeks in Mineral County, CO
July in the garden — Mineral County, Colorado
Welcome to July in Zone 5a. These are the moves that will have the biggest impact on your growing season.
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Begin indoor sowing: leeks
Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.
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Direct-sow leeks for cool weather
Mid-season soil is hot. Sow a bit deeper than the packet suggests to find cooler, damper ground.
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.
Mineral County, Colorado is in USDA Zone 5a. The average last spring frost is June 10 and the first fall frost is September 13, giving you a growing season of approximately 95 days.
At an elevation of 7,809 feet, Mineral County receives approximately 12.8 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Leeks to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Leeks successfully. Mulch heavily to conserve soil moisture.
Mineral County Soil Profile
Soil Type
Loam
Soil pH
6.8-8
Drainage
Well Drained
Leeks 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.
Soil Compatibility in Mineral County
How your county's soil matches Leeks's growing requirements.
Soil pH
Your soil pH (6.8–8.0) is more alkaline than Leeks prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Mineral County is excellent for Leeks — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Leeks.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Leeks.
How to Plant Leeks
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Leeks Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Leeks
Leeks needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.
| Month | Leeks Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | — | 1.2" | 0" | ❄️ Dormant |
| Apr | — | 1.1" | 0" | ❄️ Dormant |
| May | — | 1.6" | 0" | ❄️ Dormant |
| Jun | 3.5" | 0.8" | 2.7" | 🚿 Regular watering |
| Jul | 3.5" | 1" | 2.5" | 🚿 Regular watering |
| Aug | 3.5" | 1.4" | 2.1" | 🚿 Regular watering |
| Sep | 3.5" | 0.9" | 2.6" | 🚿 Regular watering |
| Oct | — | 1.2" | 0" | ❄️ Dormant |
| Nov | — | 0.9" | 0" | ❄️ Dormant |
| Dec | — | 0.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Mineral County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Leeks Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Leeks Planting Timeline — Mineral County, CO
Leeks Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | May 6 | May 6 – May 20 |
| Transplant Outdoors | June 10 | Jun 10 – Jun 24 |
| Direct Sow | May 27 | May 27 – Jun 17 |
| Harvest | September 9 | Sep 9 – Nov 25 |
| Fall Sowing | July 5 | Jul 5 – Jul 19 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Start Indoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Fall Sowing |
| August | — |
| September | Harvest |
| October | Harvest |
| November | Harvest |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · 1-2 times/week
📅 Days to Maturity
90–150 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5a
📆 Growing Season
95 days in Mineral County
Growing Tips for Leeks in Mineral County
Direct sow Leeks outdoors after June 10 in Mineral County when soil has warmed and frost danger has passed.
Your 95.0-day growing season in Mineral County is tight for Leeks (90.0-150.0 days to maturity). Start indoors and choose early-maturing varieties.
Common pests for Leeks in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.
General growing tips
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
Check more plant combinations with our Companion Planting Checker →
Leeks in Other Locations
Frequently Asked Questions
When should I plant Leeks in Mineral County, CO?
Mineral County is in Zone 5a with an average last frost of June 10. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.
What planting zone is Mineral County, CO?
Mineral County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 10 and first fall frost is September 13.
When should I plant Leeks in Mineral County, CO?
In Mineral County, CO, plant Leeks after the last frost (around June 10) and before the first frost (around September 13). Best results when soil holds above 50°F.
What growing zone is Mineral County, CO for Leeks?
Mineral County sits in USDA Zone 5a. Leeks grows reliably in zones 3a through 10b, so it's a good fit here.
Can Leeks grow in Mineral County's climate?
Yes — Leeks grows well in Mineral County's temperate climate. Mineral County averages a 95-day frost-free season, with last frost around June 10 and first frost around September 13.
Your Mineral County Garden Planner — Free
A 22-page printable planner built for Mineral County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.