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When to Plant Soybeans in Bannock County, ID

Soybeans (edamame) are a high-protein legume that fixes nitrogen in the soil. Fresh green soybeans harvested at the edamame stage are a nutritious snack.

Bannock County, Idaho is in USDA Zone 5a. The average last spring frost is May 23 and the first fall frost is September 24, giving you a growing season of approximately 124 days.

At an elevation of 5,637 feet, Bannock County receives approximately 13.1 inches of rainfall annually with predominantly loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Soybeans to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Soybeans successfully. Mulch heavily to conserve soil moisture.

Bannock County, ID (Zone 5a) Short season
124 days
Last Spring Frost May 23
124 growing days
First Fall Frost September 24

Bannock County Soil Profile

Soil Type

Loam

Soil pH

6.7-8.1

Drainage

Well Drained

Monthly Watering Guide for Soybeans

Soybeans needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Soybeans Needs Rainfall You Supplement Action
Jan โ€” 1" 0" โ„๏ธ Dormant
Feb โ€” 0.8" 0" โ„๏ธ Dormant
Mar โ€” 1.1" 0" โ„๏ธ Dormant
Apr โ€” 1.4" 0" โ„๏ธ Dormant
May 4.3" 1.5" 2.8" ๐Ÿšฟ Regular watering
Jun 4.3" 0.9" 3.4" ๐Ÿšฟ Regular watering
Jul 4.3" 1.1" 3.2" ๐Ÿšฟ Regular watering
Aug 4.3" 1.4" 2.9" ๐Ÿšฟ Regular watering
Sep 4.3" 1" 3.3" ๐Ÿšฟ Regular watering
Oct โ€” 1" 0" โ„๏ธ Dormant
Nov โ€” 1" 0" โ„๏ธ Dormant
Dec โ€” 0.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Bannock County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Soybeans Planting Timeline โ€” Bannock County, ID

Soybeans Planting Calendar

Activity When Date Range
Direct Sow May 30 May 30 โ€“ Jun 20
Harvest August 22 Aug 22 โ€“ Oct 17

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Direct Sow
June Direct Sow
July โ€”
August Harvest
September Harvest
October Harvest
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

Moderate โ€” regular watering

๐Ÿ“… Days to Maturity

80โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

124 days in Bannock County

Growing Tips for Bannock County

Direct sow after soil warms to 60F. Plant in blocks rather than rows for better pollination. Harvest for edamame when pods are plump and bright green.

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 Soybeans in Bannock County, ID?

Bannock County is in Zone 5a with an average last frost of May 23. Plan your Soybeans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Bannock County, ID?

Bannock County, Idaho is in USDA Hardiness Zone 5a. The average last spring frost is May 23 and first fall frost is September 24.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Bannock County gardeners in Zone 5a 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 Bannock County, ID. Local conditions may vary. Last updated: April 2026.