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When to Plant Soybeans in Montgomery County, AR

Montgomery County, Arkansas Zone 8a May

Top priorities for Montgomery County, Arkansas gardeners in May

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost March 27
Avg. first frost November 6
Soil temp (4") 69°F
Watering Low
Pest pressure Moderate
Daylight 13.8 hrs
Coming up in June — start thinking about
  • First harvests: soybeans

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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, Arkansas is in USDA Zone 8a. The average last spring frost is March 27 and the first fall frost is November 6, giving you a growing season of approximately 224 days.

At an elevation of 850 feet, Montgomery County receives approximately 46.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Soybeans during the growing season.

Montgomery County, AR (Zone 8a) Long season
224 days
Last Spring Frost March 27
224 growing days
First Fall Frost November 6

Montgomery County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (87 days to spare)
Transplant: Mar 17 🍅 Harvest: Jun 9 – Aug 4
Recommended (50%) ✓ Fits season (84 days to spare)
Transplant: Mar 27 🍅 Harvest: Jun 19 – Aug 14
Safe Start (90%) ✓ Fits season (84 days to spare)
Transplant: Apr 15 🍅 Harvest: Jul 8 – Sep 2

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 Montgomery County

How your county's soil matches Soybeans's growing requirements.

Soil pH

Your soil pH (5.3–6.9) overlaps with Soybeans's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Montgomery County is excellent for Soybeans — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Soybeans.

How to Plant Soybeans

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Succession Planting Soybeans

3
successive plantings in your 224-day season

Sow every 9.1 weeks. Last sowing by Jul 09 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 252 gal / 100 sq ft

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 3.4" 0" ❄️ Dormant
Feb 3.2" 0" ❄️ Dormant
Mar 4.3" 4.4" 0" ✅ Rainfall sufficient
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 4.4" 0" ✅ Rainfall sufficient
Jul 4.3" 4.8" 0" ✅ Rainfall sufficient
Aug 4.3" 4.9" 0" ✅ Rainfall sufficient
Sep 4.3" 3.6" 0.7" 💧 Light watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 4.3" 3.9" 0.4" 💧 Light watering
Dec 3.3" 0" ❄️ Dormant

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

Soybeans 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.

Soybeans needs ~1,600 GDD — county provides 3,584 GDD Excellent fit

Soybeans Planting Timeline — Montgomery County, AR

Soybeans Planting Calendar

Activity When Date Range
Direct Sow April 3 Apr 3 – Apr 24
Harvest June 26 Jun 26 – Aug 21

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

224 days in Montgomery County

Growing Tips for Soybeans in Montgomery County

Direct sow Soybeans outdoors after March 27 in Montgomery County when soil has warmed and frost danger has passed.

Common pests for Soybeans in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

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, AR?

Montgomery County is in Zone 8a with an average last frost of March 27. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Montgomery County, AR?

Montgomery County, Arkansas is in USDA Hardiness Zone 8a. The average last spring frost is March 27 and first fall frost is November 6.

🌱

Your Montgomery County Garden Planner — Free

A 24-page printable planner built for Montgomery County (Zone 8a). 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, AR. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.