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When to Plant Leeks in Calgary, AB

Leeks

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.

Calgary, Alberta is in USDA Zone 5a. The average last spring frost is May 7 and the first fall frost is October 14, giving you a growing season of approximately 160 days.

At an elevation of 3,428 feet, Calgary receives approximately 26.9 inches of rainfall annually with predominantly dark brown chernozem soil. Summer highs average 75°F, so choose short-season varieties of Leeks to ensure they mature before fall.

Calgary, AB (Zone 5a) Moderate season
160 days
Last Spring Frost May 7
160 growing days
First Fall Frost October 14

Calgary Soil Profile

Soil Type

Dark Brown Chernozem

Soil pH

6.0-7.0

Drainage

Well Drained

Monthly Watering Guide for Leeks

Leeks needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Leeks Needs Rainfall You Supplement Action
Jan 1.1" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.5" 0" ❄️ Dormant
May 4.3" 3.3" 1" 💧 Light watering
Jun 4.3" 3.3" 1" 💧 Light watering
Jul 4.3" 3.1" 1.2" 💧 Light watering
Aug 4.3" 2.9" 1.4" 💧 Light watering
Sep 4.3" 2.1" 2.2" 🚿 Regular watering
Oct 4.3" 2" 2.3" 🚿 Regular watering
Nov 1.9" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Calgary). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Leeks Planting Timeline — Calgary, AB

Leeks Planting Calendar

Activity When Date Range
Start Indoors April 2 Apr 2 – Apr 16
Transplant Outdoors May 7 May 7 – May 21
Direct Sow April 23 Apr 23 – May 14
Harvest August 6 Aug 6 – Oct 22
Fall Sowing August 5 Aug 5 – Aug 19

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June
July
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 5a

📆 Growing Season

160 days in Calgary

Growing Tips for Calgary

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 Calgary, AB?

Calgary is in Zone 5a with an average last frost of May 7. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.

What planting zone is Calgary, AB?

Calgary, Alberta is in USDA Hardiness Zone 5a. The average last spring frost is May 7 and first fall frost is October 14.

🌱

Your Calgary Garden Planner — Free

A 22-page printable planner built for Calgary (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.