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When to plant Soybeans in Montgomery County, IA

For Montgomery County, gardeners: plant Soybeans May 3 through May 24 once soil reads 50°F.

When to Plant Soybeans in Montgomery County, IA

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.

Montgomery County, Iowa is in USDA Zone 5b. The average last spring frost is April 26 and the first fall frost is October 7, giving you a growing season of approximately 164 days.

At an elevation of 1,271 feet, Montgomery County receives approximately 31.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Soybeans to ensure they mature before fall.

Montgomery County, IA (Zone 5b) Moderate season
164 days
Last Spring Frost April 26
164 growing days
First Fall Frost October 7

Montgomery County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.8

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 1.4" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 4.3" 3.1" 1.2" 💧 Light watering
May 4.3" 3.2" 1.1" 💧 Light watering
Jun 4.3" 4.2" 0.1" 💧 Light watering
Jul 4.3" 3.5" 0.8" 💧 Light watering
Aug 4.3" 2.9" 1.4" 💧 Light watering
Sep 4.3" 2.5" 1.8" 💧 Light watering
Oct 4.3" 2.6" 1.7" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Montgomery County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Soybeans Planting Timeline — Montgomery County, IA

Soybeans Planting Calendar

Activity When Date Range
Direct Sow May 3 May 3 – May 24
Harvest July 26 Jul 26 – Sep 20

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

164 days in Montgomery County

Growing Tips for Montgomery 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 Montgomery County, IA?

Montgomery County is in Zone 5b with an average last frost of April 26. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Montgomery County, IA?

Montgomery County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 26 and first fall frost is October 7.

When should I plant Soybeans in Montgomery County, IA?

In Montgomery County, IA, plant Soybeans after the last frost (around April 26) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Montgomery County, IA for Soybeans?

Montgomery County sits in USDA Zone 5b. Soybeans grows reliably in zones 3a through 10b, so it's a good fit here.

Can Soybeans grow in Montgomery County's climate?

Yes — Soybeans grows well in Montgomery County's temperate climate. Montgomery County averages a 164-day frost-free season, with last frost around April 26 and first frost around October 7.

🌱

Your Montgomery County Garden Planner — Free

A 22-page printable planner built for Montgomery County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Montgomery County, IA. Local conditions may vary. Last updated: July 2026.

Sources & credits

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