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When to Plant Fava Beans in Weld County, CO

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.

Weld County, Colorado is in USDA Zone 5a. The average last spring frost is May 2 and the first fall frost is October 7, giving you a growing season of approximately 158 days.

At an elevation of 6,992 feet, Weld County receives approximately 18.8 inches of rainfall annually with predominantly loam soil. Summer highs average 87ยฐF, providing good warmth for Fava Beans during the growing season. With low rainfall, drip irrigation is essential for growing Fava Beans successfully. Mulch heavily to conserve soil moisture.

Weld County, CO (Zone 5a) Moderate season
158 days
Last Spring Frost May 2
158 growing days
First Fall Frost October 7

Weld County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (39 days to spare)
Start indoors: Mar 23 Transplant: Apr 27 🍅 Harvest: Jul 13 – Aug 24
Recommended (50%) ✓ Fits season (39 days to spare)
Start indoors: Mar 28 Transplant: May 2 🍅 Harvest: Jul 18 – Aug 29
Safe Start (90%) ✓ Fits season (34 days to spare)
Start indoors: Apr 14 Transplant: May 19 🍅 Harvest: Aug 4 – Sep 15

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 Weld County

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

Soil pH

Your soil pH (6.6โ€“8.1) 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 Weld County is excellent for Fava Beans โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Fava Beans.

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.

Succession Planting Fava Beans

2
successive plantings in your 158-day season

Sow every 8.6 weeks. Last sowing by Jun 29 to harvest before frost.

For a dedicated fall crop, sow by Jul 29.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 844 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€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1" 0" โ„๏ธ Dormant
Mar โ€” 1.5" 0" โ„๏ธ Dormant
Apr โ€” 2.1" 0" โ„๏ธ Dormant
May 4.3" 2.3" 2" ๐Ÿ’ง Light watering
Jun 4.3" 1.4" 2.9" ๐Ÿšฟ Regular watering
Jul 4.3" 1.7" 2.6" ๐Ÿšฟ Regular watering
Aug 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering
Sep 4.3" 1.7" 2.6" ๐Ÿšฟ Regular watering
Oct 4.3" 1.7" 2.6" ๐Ÿšฟ Regular watering
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€“Oct in Weld 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 ~1,334 GDD — county provides 2,409 GDD Excellent fit

Fava Beans Planting Timeline โ€” Weld County, CO

Fava Beans Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 โ€“ Apr 11
Transplant Outdoors May 2 May 2 โ€“ May 16
Direct Sow April 18 Apr 18 โ€“ May 9
Harvest July 18 Jul 18 โ€“ Aug 29
Fall Sowing July 29 Jul 29 โ€“ Aug 12

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 Fall Sowing 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 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 5a

๐Ÿ“† Growing Season

158 days in Weld County

Growing Tips for Fava Beans in Weld County

Direct sow Fava Beans outdoors after May 02 in Weld 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.

Weld County receives only 19" 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 Weld County, CO?

Weld County is in Zone 5a with an average last frost of May 2. Plan your Fava Beans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Weld County, CO?

Weld County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is May 2 and first fall frost is October 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Weld County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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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 Weld County, CO. Local conditions may vary. Last updated: April 2026.