When to Plant Fava Beans in Lake 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.
Lake County, Montana is in USDA Zone 5a. The average last spring frost is May 31 and the first fall frost is September 12, giving you a growing season of approximately 104 days.
At an elevation of 6,938 feet, Lake County receives approximately 12.8 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, 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.
Lake County Soil Profile
Soil Type
Loam
Soil pH
6.6-7.7
Drainage
Well Drained
Plant Planting Risk Windows
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 Lake County
How your county's soil matches Fava Beans's growing requirements.
Soil pH
Your soil pH (6.6–7.7) is more alkaline than Fava Beans prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Lake County is excellent for Fava Beans — 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
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Plant Water Budget
Water stress score is 8/10 — 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" | 0" | ❄️ Dormant |
| Feb | — | 0.7" | 0" | ❄️ Dormant |
| Mar | — | 1" | 0" | ❄️ Dormant |
| Apr | — | 1.3" | 0" | ❄️ Dormant |
| May | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Jun | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Jul | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Aug | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| Sep | 4.3" | 1.1" | 3.2" | 🚿 Regular watering |
| Oct | — | 1.1" | 0" | ❄️ Dormant |
| Nov | — | 1" | 0" | ❄️ Dormant |
| Dec | — | 0.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Lake 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 Planting Timeline — Lake County, MT
Fava Beans Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 26 | Apr 26 – May 10 |
| Transplant Outdoors | May 31 | May 31 – Jun 14 |
| Direct Sow | May 17 | May 17 – Jun 7 |
| Harvest | August 16 | Aug 16 – Sep 27 |
| Fall Sowing | July 4 | Jul 4 – Jul 18 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Start Indoors 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 · 1-2 times/week
📅 Days to Maturity
75–100 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5a
📆 Growing Season
104 days in Lake County
Growing Tips for Fava Beans in Lake County
Direct sow Fava Beans outdoors after May 31 in Lake County when soil has warmed and frost danger has passed.
Your 104.0-day growing season in Lake County is tight for Fava Beans (75.0-100.0 days to maturity). Start indoors and choose early-maturing varieties.
Common pests for Fava Beans in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.
Lake County receives only 13" of rain annually. Fava Beans needs consistent moisture — 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
Check more plant combinations with our Companion Planting Checker →
Fava Beans in Other Locations
Frequently Asked Questions
When should I plant Fava Beans in Lake County, MT?
Lake County is in Zone 5a with an average last frost of May 31. Plan your Fava Beans planting based on this frost date — see the calendar above for exact timing.
What planting zone is Lake County, MT?
Lake County, Montana is in USDA Hardiness Zone 5a. The average last spring frost is May 31 and first fall frost is September 12.
Plan Your Garden with Confidence
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