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When to Plant Fava Beans in Sherburne County, MN

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.

Sherburne County, Minnesota is in USDA Zone 4a. The average last spring frost is May 1 and the first fall frost is October 6, giving you a growing season of approximately 158 days.

At an elevation of 568 feet, Sherburne County receives approximately 38.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Fava Beans to ensure they mature before fall.

Sherburne County, MN (Zone 4a) Moderate season
158 days
Last Spring Frost May 1
158 growing days
First Fall Frost October 6

Sherburne County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (37 days to spare)
Start indoors: Mar 14 Transplant: Apr 25 🍅 Harvest: Jul 11 – Aug 22
Recommended (50%) ✓ Fits season (39 days to spare)
Start indoors: Mar 20 Transplant: May 1 🍅 Harvest: Jul 17 – Aug 28
Safe Start (90%) ✓ Fits season (35 days to spare)
Start indoors: Apr 6 Transplant: May 18 🍅 Harvest: Aug 3 – Sep 14

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 Sherburne County

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

Soil pH

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

Soil Texture

The silt loam soil in Sherburne County is excellent for Fava Beans โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Fava Beans.

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.

Succession Planting Fava Beans

2
successive plantings in your 158-day season

Sow every 8.6 weeks. Last sowing by Jun 28 to harvest before frost.

For a dedicated fall crop, sow by Jul 14.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 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€” 1.7" 0" โ„๏ธ Dormant
Feb โ€” 2" 0" โ„๏ธ Dormant
Mar โ€” 2.6" 0" โ„๏ธ Dormant
Apr โ€” 3.8" 0" โ„๏ธ Dormant
May 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Jun 4.3" 4.9" 0" โœ… Rainfall sufficient
Jul 4.3" 4.1" 0.2" ๐Ÿ’ง Light watering
Aug 4.3" 4.1" 0.2" ๐Ÿ’ง Light watering
Sep 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Oct 4.3" 2.8" 1.5" ๐Ÿ’ง Light watering
Nov โ€” 2.7" 0" โ„๏ธ Dormant
Dec โ€” 1.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Sherburne County). 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 ~1,006 GDD — county provides 1,817 GDD Excellent fit

Fava Beans Planting Timeline โ€” Sherburne County, MN

Fava Beans Planting Calendar

Activity When Date Range
Start Indoors March 20 Mar 20 โ€“ Apr 3
Transplant Outdoors May 1 May 1 โ€“ May 15
Direct Sow April 24 Apr 24 โ€“ May 15
Harvest July 17 Jul 17 โ€“ Aug 28
Fall Sowing July 14 Jul 14 โ€“ Jul 28

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 Fall Sowing Harvest
August Harvest
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

75โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

158 days in Sherburne County

Growing Tips for Fava Beans in Sherburne County

Direct sow Fava Beans outdoors after May 01 in Sherburne 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 Sherburne County, MN?

Sherburne County is in Zone 4a with an average last frost of May 1. Plan your Fava Beans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Sherburne County, MN?

Sherburne County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 1 and first fall frost is October 6.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Sherburne County gardeners in Zone 4a 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 Sherburne County, MN. Local conditions may vary. Last updated: April 2026.