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When to Plant Leeks in Elbert 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.

Elbert County, Colorado is in USDA Zone 5a. The average last spring frost is May 12 and the first fall frost is October 3, giving you a growing season of approximately 144 days.

At an elevation of 5,587 feet, Elbert County receives approximately 22.1 inches of rainfall annually with predominantly loam soil. Summer highs average 87ยฐF, providing good warmth for Leeks during the growing season.

Elbert County, CO (Zone 5a) Short season
144 days
Last Spring Frost May 12
144 growing days
First Fall Frost October 3

Elbert County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 29 Transplant: May 3 🍅 Harvest: Aug 2 – Oct 18
Recommended (50%) ✗ May not fit
Start indoors: Apr 7 Transplant: May 12 🍅 Harvest: Aug 11 – Oct 27
Safe Start (90%) ✗ May not fit
Start indoors: Apr 23 Transplant: May 28 🍅 Harvest: Aug 27 – Nov 12

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 Elbert County

How your county's soil matches Leeks's growing requirements.

Soil pH

Your soil pH (6.2โ€“7.7) overlaps with Leeks's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The loam soil in Elbert County is excellent for Leeks โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Leeks.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Leeks.

How to Plant Leeks

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 608 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” 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 โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.2" 0" โ„๏ธ Dormant
Mar โ€” 1.8" 0" โ„๏ธ Dormant
Apr โ€” 2.2" 0" โ„๏ธ Dormant
May 3.5" 2.4" 1.1" ๐Ÿ’ง Light watering
Jun 3.5" 1.7" 1.8" ๐Ÿšฟ Regular watering
Jul 3.5" 1.9" 1.6" ๐Ÿ’ง Light watering
Aug 3.5" 2.3" 1.2" ๐Ÿ’ง Light watering
Sep 3.5" 2" 1.5" ๐Ÿ’ง Light watering
Oct 3.5" 1.9" 1.6" ๐Ÿ’ง Light watering
Nov โ€” 1.8" 0" โ„๏ธ Dormant
Dec โ€” 1.4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Elbert County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 needs ~1,830 GDD — county provides 2,196 GDD Good fit

Leeks Planting Timeline โ€” Elbert County, CO

Leeks Planting Calendar

Activity When Date Range
Start Indoors April 7 Apr 7 โ€“ Apr 21
Transplant Outdoors May 12 May 12 โ€“ May 26
Direct Sow April 28 Apr 28 โ€“ May 19
Harvest August 11 Aug 11 โ€“ Oct 27
Fall Sowing July 25 Jul 25 โ€“ Aug 8

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June โ€”
July Fall Sowing
August Fall Sowing Harvest
September Harvest
October Harvest
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.8"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

90โ€“150 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

144 days in Elbert County

Growing Tips for Leeks in Elbert County

Direct sow Leeks outdoors after May 12 in Elbert County when soil has warmed and frost danger has passed.

Your 144.0-day growing season in Elbert 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

  • Peas
  • Green Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Leeks in Elbert County, CO?

Elbert County is in Zone 5a with an average last frost of May 12. Plan your Leeks planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Elbert County, CO?

Elbert County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is May 12 and first fall frost is October 3.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Elbert County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Elbert County, CO. Local conditions may vary. Last updated: April 2026.