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When to Plant Fava Beans in Chouteau County, MT

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.

Chouteau County, Montana is in USDA Zone 4a. The average last spring frost is May 12 and the first fall frost is September 27, giving you a growing season of approximately 138 days.

At an elevation of 5,753 feet, Chouteau County receives approximately 15 inches of rainfall annually with predominantly loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Fava Beans to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Fava Beans successfully. Mulch heavily to conserve soil moisture.

Chouteau County, MT (Zone 4a) Short season
138 days
Last Spring Frost May 12
138 growing days
First Fall Frost September 27

Chouteau County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (16 days to spare)
Start indoors: Mar 27 Transplant: May 8 🍅 Harvest: Jul 24 – Sep 4
Recommended (50%) ✓ Fits season (19 days to spare)
Start indoors: Mar 31 Transplant: May 12 🍅 Harvest: Jul 28 – Sep 8
Safe Start (90%) ✓ Fits season (12 days to spare)
Start indoors: Apr 21 Transplant: Jun 2 🍅 Harvest: Aug 18 – Sep 29

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 801 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Fava Beans needs ~1,138 GDD — county provides 1,794 GDD Excellent fit

Fava Beans Planting Timeline โ€” Chouteau County, MT

Fava Beans Planting Calendar

Activity When Date Range
Start Indoors March 31 Mar 31 โ€“ Apr 14
Transplant Outdoors May 12 May 12 โ€“ May 26
Direct Sow May 5 May 5 โ€“ May 26
Fall Sowing July 5 Jul 5 โ€“ Jul 19
Harvest July 28 Jul 28 โ€“ Sep 8

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
May Transplant Outdoors Direct Sow
June โ€”
July Fall Sowing Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

75โ€“100 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 4a

Growing Season

138 days

Growing Tips for Chouteau County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Fava Beans in Chouteau County, MT?

Chouteau County is in Zone 4a with an average last frost of May 12. Plan your Fava Beans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Chouteau County, MT?

Chouteau County, Montana is in USDA Hardiness Zone 4a. The average last spring frost is May 12 and first fall frost is September 27.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Chouteau County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

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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 Chouteau County, MT. Local conditions may vary. Last updated: April 2026.