Blog

When to Plant Fava Beans in Lethbridge, AB

Fava beans are a cool-season legume with large, meaty beans inside thick pods. They fix nitrogen in the soil and are one of the oldest cultivated crops.

Lethbridge, Alberta is in USDA Zone 5a. The average last spring frost is May 5 and the first fall frost is October 12, giving you a growing season of approximately 160 days.

At an elevation of 2,985 feet, Lethbridge receives approximately 23.7 inches of rainfall annually with predominantly dark brown chernozem soil. Summer highs average 74ยฐF, so choose short-season varieties of Fava Beans to ensure they mature before fall.

Lethbridge, AB (Zone 5a) Moderate season
160 days
Last Spring Frost May 5
160 growing days
First Fall Frost October 12

Lethbridge Soil Profile

Soil Type

Dark Brown Chernozem

Soil pH

6.0-7.0

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (64 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jul 1 – Aug 12
Recommended (50%) ✓ Fits season (64 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jul 1 – Aug 12
Safe Start (90%) ✓ Fits season (64 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jul 1 – Aug 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.

How to Plant Fava Beans

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
1.0″/week
Rainfall provides
0.6″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 538 gal / 100 sq ft

Monthly Watering Guide for Fava Beans

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

Month Fava Beans Needs Rainfall You Supplement Action
Jan โ€” 0.9" 0" โ„๏ธ Dormant
Feb โ€” 1" 0" โ„๏ธ Dormant
Mar โ€” 1.8" 0" โ„๏ธ Dormant
Apr โ€” 2.4" 0" โ„๏ธ Dormant
May 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
Jun 4.3" 2.8" 1.5" ๐Ÿ’ง Light watering
Jul 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
Aug 4.3" 2.3" 2" ๐Ÿ’ง Light watering
Sep 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Oct 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Nov โ€” 1.5" 0" โ„๏ธ Dormant
Dec โ€” 1.4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Lethbridge). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Fava Beans 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.

Fava Beans needs ~481 GDD — county provides 880 GDD Excellent fit

Fava Beans Planting Timeline โ€” Lethbridge, AB

Fava Beans Planting Calendar

Activity When Date Range
Start Indoors March 31 Mar 31 โ€“ Apr 14
Transplant Outdoors May 5 May 5 โ€“ May 19
Direct Sow April 21 Apr 21 โ€“ May 12
Harvest July 21 Jul 21 โ€“ Sep 1
Fall Sowing August 3 Aug 3 โ€“ Aug 17

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

75โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

160 days in Lethbridge

Growing Tips for Fava Beans in Lethbridge

Common pests for Fava Beans in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

Lethbridge receives only 24" of rain annually. Fava Beans needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow as early as soil can be worked in spring. Pinch growing tips when pods begin to form to redirect energy and reduce aphid problems. Stake tall varieties.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Fava Beans in Lethbridge, AB?

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

What planting zone is Lethbridge, AB?

Lethbridge, Alberta is in USDA Hardiness Zone 5a. The average last spring frost is May 5 and first fall frost is October 12.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Lethbridge 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 Lethbridge, AB. Local conditions may vary. Last updated: April 2026.