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When to Plant Fava Beans in Cook County, MN

Cook County, Minnesota Zone 3b May

May in Cook County, Minnesota — your action list

Here's what deserves your attention in Cook County, Minnesota this month. Everything below is tailored to Zone 3b and timed around your local frost dates.

Avg. last frost May 20
Avg. first frost September 29
Soil temp (4") 48°F
Watering Moderate
Pest pressure Low
Daylight 14.9 hrs
  1. Transplant fava beans outside

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

  2. Plant fava beans from seed, right in the garden

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

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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.

Cook County, Minnesota is in USDA Zone 3b. The average last spring frost is May 20 and the first fall frost is September 29, giving you a growing season of approximately 132 days.

At an elevation of 1,068 feet, Cook County receives approximately 34.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Fava Beans to ensure they mature before fall.

Cook County, MN (Zone 3b) Short season
132 days
Last Spring Frost May 20
132 growing days
First Fall Frost September 29

Cook County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (13 days to spare)
Start indoors: Apr 3 Transplant: May 15 🍅 Harvest: Jul 31 – Sep 11
Recommended (50%) ✓ Fits season (13 days to spare)
Start indoors: Apr 8 Transplant: May 20 🍅 Harvest: Aug 5 – Sep 16
Safe Start (90%) ✓ Fits season (16 days to spare)
Start indoors: Apr 19 Transplant: May 31 🍅 Harvest: Aug 16 – Sep 27

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 Cook County

How your county's soil matches Fava Beans's growing requirements.

Soil pH

Your soil pH (6.1–7.1) overlaps with Fava Beans's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Cook County is excellent for Fava Beans — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.4%) — Fava Beans will thrive.

How to Plant Fava Beans

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

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.4" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 3.5" 0" ❄️ Dormant
May 4.3" 3.4" 0.9" 💧 Light watering
Jun 4.3" 4.7" 0" ✅ Rainfall sufficient
Jul 4.3" 3.9" 0.4" 💧 Light watering
Aug 4.3" 3" 1.3" 💧 Light watering
Sep 4.3" 3.2" 1.1" 💧 Light watering
Oct 2.7" 0" ❄️ Dormant
Nov 2.5" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Cook County). Supplement amounts are based on average rainfall — 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" — 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.

Fava Beans needs ~875 GDD — county provides 1,320 GDD Excellent fit

Fava Beans Planting Timeline — Cook County, MN

Fava Beans Planting Calendar

Activity When Date Range
Start Indoors April 8 Apr 8 – Apr 22
Transplant Outdoors May 20 May 20 – Jun 3
Direct Sow May 13 May 13 – Jun 3
Harvest August 5 Aug 5 – Sep 16
Fall Sowing July 7 Jul 7 – Jul 21

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

75–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 3b

📆 Growing Season

132 days in Cook County

Growing Tips for Fava Beans in Cook County

Direct sow Fava Beans outdoors after May 20 in Cook County when soil has warmed and frost danger has passed.

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

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 Cook County, MN?

Cook County is in Zone 3b with an average last frost of May 20. Plan your Fava Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cook County, MN?

Cook County, Minnesota is in USDA Hardiness Zone 3b. The average last spring frost is May 20 and first fall frost is September 29.

🌱

Your Cook County Garden Planner — Free

A 24-page printable planner built for Cook County (Zone 3b). 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 Cook County, MN. Local conditions may vary. Last updated: May 2026.

Sources & credits

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