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When to Plant Soybeans in Hamilton County, KS

Hamilton County, Kansas Zone 6a May

What to do in May

Your garden in Hamilton County, Kansas is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 27
Avg. first frost October 12
Soil temp (4") 64°F
Watering Moderate
Pest pressure Low
Daylight 14.1 hrs
  1. Put soybeans seeds straight in the ground

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

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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.

Hamilton County, Kansas is in USDA Zone 6a. The average last spring frost is April 27 and the first fall frost is October 12, giving you a growing season of approximately 168 days.

At an elevation of 871 feet, Hamilton County receives approximately 24 inches of rainfall annually with predominantly loam soil. Summer highs average 92°F, providing good warmth for Soybeans during the growing season.

Hamilton County, KS (Zone 6a) Moderate season
168 days
Last Spring Frost April 27
168 growing days
First Fall Frost October 12
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Hamilton County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (29 days to spare)
Transplant: Apr 21 🍅 Harvest: Jul 14 – Sep 8
Recommended (50%) ✓ Fits season (28 days to spare)
Transplant: Apr 27 🍅 Harvest: Jul 20 – Sep 14
Safe Start (90%) ✓ Fits season (29 days to spare)
Transplant: May 12 🍅 Harvest: Aug 4 – Sep 29

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 Hamilton County

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

Soil pH

Your soil pH (6.3–7.8) is more alkaline than Soybeans prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) — Soybeans will thrive.

How to Plant Soybeans

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

Succession Planting Soybeans

2
successive plantings in your 168-day season

Sow every 9.1 weeks. Last sowing by Jun 14 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 718 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — consider drought-tolerant varieties and mulching

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 1.6" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 4.3" 2.8" 1.5" 💧 Light watering
May 4.3" 3" 1.3" 💧 Light watering
Jun 4.3" 1.5" 2.8" 🚿 Regular watering
Jul 4.3" 2.1" 2.2" 🚿 Regular watering
Aug 4.3" 2.6" 1.7" 💧 Light watering
Sep 4.3" 1.7" 2.6" 🚿 Regular watering
Oct 4.3" 2" 2.3" 🚿 Regular watering
Nov 1.7" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Hamilton 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 ~1,900 GDD — county provides 3,192 GDD Excellent fit

Soybeans Planting Timeline — Hamilton County, KS

Soybeans Planting Calendar

Activity When Date Range
Direct Sow May 4 May 4 – May 25
Harvest July 27 Jul 27 – Sep 21

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
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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: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

168 days in Hamilton County

Growing Tips for Soybeans in Hamilton County

Direct sow Soybeans outdoors after April 27 in Hamilton 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.

Hamilton County receives only 24" of rain annually. Soybeans needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Hamilton County, KS?

Hamilton County is in Zone 6a with an average last frost of April 27. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hamilton County, KS?

Hamilton County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 27 and first fall frost is October 12.

🌱

Your Hamilton County Garden Planner — Free

A 24-page printable planner built for Hamilton County (Zone 6a). 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 Hamilton County, KS. 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.