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When to Plant Fava Beans in Weston County, WY

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.

Weston County, Wyoming is in USDA Zone 4a. The average last spring frost is May 16 and the first fall frost is September 26, giving you a growing season of approximately 133 days.

At an elevation of 5,889 feet, Weston County receives approximately 20.7 inches of rainfall annually with predominantly loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Fava Beans to ensure they mature before fall.

Weston County, WY (Zone 4a) Short season
133 days
Last Spring Frost May 16
133 growing days
First Fall Frost September 26

Weston County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (10 days to spare)
Start indoors: Mar 31 Transplant: May 12 🍅 Harvest: Jul 28 – Sep 8
Recommended (50%) ✓ Fits season (14 days to spare)
Start indoors: Apr 4 Transplant: May 16 🍅 Harvest: Aug 1 – Sep 12
Safe Start (90%) ✓ Fits season (17 days to spare)
Start indoors: Apr 17 Transplant: May 29 🍅 Harvest: Aug 14 – Sep 25

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 Weston County

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

Soil pH

Your soil pH (6.7โ€“7.7) is more alkaline than Fava Beans prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). 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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 492 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” 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 โ€” 1.5" 0" โ„๏ธ Dormant
Feb โ€” 1.4" 0" โ„๏ธ Dormant
Mar โ€” 1.7" 0" โ„๏ธ Dormant
Apr โ€” 2.3" 0" โ„๏ธ Dormant
May 4.3" 2.3" 2" ๐Ÿ’ง Light watering
Jun 4.3" 1.5" 2.8" ๐Ÿšฟ Regular watering
Jul 4.3" 1.9" 2.4" ๐Ÿšฟ Regular watering
Aug 4.3" 2.2" 2.1" ๐Ÿ’ง Light watering
Sep 4.3" 1.6" 2.7" ๐Ÿšฟ Regular watering
Oct โ€” 1.9" 0" โ„๏ธ Dormant
Nov โ€” 1.2" 0" โ„๏ธ Dormant
Dec โ€” 1.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Weston 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 ~941 GDD — county provides 1,429 GDD Excellent fit

Fava Beans Planting Timeline โ€” Weston County, WY

Fava Beans Planting Calendar

Activity When Date Range
Start Indoors April 4 Apr 4 โ€“ Apr 18
Transplant Outdoors May 16 May 16 โ€“ May 30
Direct Sow May 9 May 9 โ€“ May 30
Harvest August 1 Aug 1 โ€“ Sep 12
Fall Sowing July 4 Jul 4 โ€“ Jul 18

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Start Indoors
May Transplant Outdoors Direct Sow
June โ€”
July Fall Sowing
August 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: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

133 days in Weston County

Growing Tips for Fava Beans in Weston County

Direct sow Fava Beans outdoors after May 16 in Weston 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.

Weston County receives only 21" 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 Weston County, WY?

Weston County is in Zone 4a with an average last frost of May 16. Plan your Fava Beans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Weston County, WY?

Weston County, Wyoming is in USDA Hardiness Zone 4a. The average last spring frost is May 16 and first fall frost is September 26.

๐ŸŒฑ

Plan Your Garden with Confidence

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