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When to Plant Soybeans in Ste. Genevieve County, MO

Ste. Genevieve County, Missouri Zone 6b May

Ste. Genevieve County, Missouri gardeners: here's your May plan

Here's what deserves your attention in Ste. Genevieve County, Missouri this month. Everything below is tailored to Zone 6b and timed around your local frost dates.

Avg. last frost April 10
Avg. first frost October 25
Soil temp (4") 64°F
Watering Low
Pest pressure Low
Daylight 14 hrs

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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.

Ste. Genevieve County, Missouri is in USDA Zone 6b. The average last spring frost is April 10 and the first fall frost is October 25, giving you a growing season of approximately 198 days.

At an elevation of 947 feet, Ste. Genevieve County receives approximately 32.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Soybeans during the growing season.

Ste. Genevieve County, MO (Zone 6b) Moderate season
198 days
Last Spring Frost April 10
198 growing days
First Fall Frost October 25

Ste. Genevieve County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (56 days to spare)
Transplant: Apr 4 🍅 Harvest: Jun 27 – Aug 22
Recommended (50%) ✓ Fits season (58 days to spare)
Transplant: Apr 10 🍅 Harvest: Jul 3 – Aug 28
Safe Start (90%) ✓ Fits season (56 days to spare)
Transplant: Apr 23 🍅 Harvest: Jul 16 – Sep 10

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 Ste. Genevieve County

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

Soil pH

Your soil pH (5.8–7.1) overlaps with Soybeans's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Ste. Genevieve 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

2
successive plantings in your 198-day season

Sow every 9.1 weeks. Last sowing by Jun 27 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 532 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 1.5" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 4.3" 2.8" 1.5" 💧 Light watering
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 4.1" 0.2" 💧 Light watering
Jul 4.3" 3.8" 0.5" 💧 Light watering
Aug 4.3" 3.3" 1" 💧 Light watering
Sep 4.3" 2.8" 1.5" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Ste. Genevieve 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 ~1,375 GDD — county provides 2,722 GDD Excellent fit

Soybeans Planting Timeline — Ste. Genevieve County, MO

Soybeans Planting Calendar

Activity When Date Range
Direct Sow April 17 Apr 17 – May 8
Harvest July 10 Jul 10 – Sep 4

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Direct Sow
May Direct Sow
June
July Harvest
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

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

198 days in Ste. Genevieve County

Growing Tips for Soybeans in Ste. Genevieve County

Direct sow Soybeans outdoors after April 10 in Ste. Genevieve 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 Ste. Genevieve County, MO?

Ste. Genevieve County is in Zone 6b with an average last frost of April 10. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Ste. Genevieve County, MO?

Ste. Genevieve County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 10 and first fall frost is October 25.

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Your Ste. Genevieve County Garden Planner — Free

A 24-page printable planner built for Ste. Genevieve County (Zone 6b). 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 Ste. Genevieve County, MO. 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.