When to plant Leeks in Broomfield County, CO
Leeks planted in Broomfield County between April 30 and May 21 matures in 90–150 days — well before the September 26 first frost. A second sowing from July 18 to August 1 extends the harvest into fall.
When to Plant Leeks in Broomfield 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.
Broomfield County, Colorado is in USDA Zone 6a. The average last spring frost is May 14 and the first fall frost is September 26, giving you a growing season of approximately 135 days.
At an elevation of 7,037 feet, Broomfield County receives approximately 13.9 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Leeks during the growing season. With low rainfall, drip irrigation is essential for growing Leeks successfully. Mulch heavily to conserve soil moisture.
Broomfield County Soil Profile
Soil Type
Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Leeks Planting Timeline — Broomfield County, CO
Leeks Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 9 | Apr 9 – Apr 23 |
| Transplant Outdoors | May 14 | May 14 – May 28 |
| Direct Sow | April 30 | Apr 30 – May 21 |
| Harvest | August 13 | Aug 13 – Oct 29 |
| Fall Sowing | July 18 | Jul 18 – Aug 1 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Fall Sowing |
| 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
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 6a
📆 Growing Season
135 days in Broomfield County
Growing Tips for Broomfield 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
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Leeks in Other Locations
Frequently Asked Questions
When should I plant Leeks in Broomfield County, CO?
Broomfield County is in Zone 6a with an average last frost of May 14. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.
What planting zone is Broomfield County, CO?
Broomfield County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 14 and first fall frost is September 26.
When should I plant Leeks in Broomfield County, CO?
In Broomfield County, CO, plant Leeks after the last frost (around May 14) and before the first frost (around September 26). Best results when soil holds above 50°F.
What growing zone is Broomfield County, CO for Leeks?
Broomfield County sits in USDA Zone 6a. Leeks grows reliably in zones 3a through 10b, so it's a good fit here.
Can Leeks grow in Broomfield County's climate?
Yes — Leeks grows well in Broomfield County's temperate climate. Broomfield County averages a 135-day frost-free season, with last frost around May 14 and first frost around September 26.
Your Broomfield County Garden Planner — Free
A 22-page printable planner built for Broomfield County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.