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When to Plant Soybeans in Jackson County, MS

Jackson County, Mississippi Zone 9a May

What to do in May

Here's what deserves your attention in Jackson County, Mississippi this month. Everything below is tailored to Zone 9a and timed around your local frost dates.

Avg. last frost March 2
Avg. first frost November 26
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 13.5 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.

Jackson County, Mississippi is in USDA Zone 9a. The average last spring frost is March 2 and the first fall frost is November 26, giving you a growing season of approximately 269 days.

At an elevation of 182 feet, Jackson County receives approximately 57.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 91°F, providing good warmth for Soybeans during the growing season. Sandy soil warms quickly in spring — great for early planting — but Soybeans will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Soybeans root diseases.

Jackson County, MS (Zone 9a) Long season
269 days
Last Spring Frost March 2
269 growing days
First Fall Frost November 26

Jackson County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.1-6.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (137 days to spare)
Transplant: Feb 14 🍅 Harvest: May 9 – Jul 4
Recommended (50%) ✓ Fits season (129 days to spare)
Transplant: Mar 2 🍅 Harvest: May 25 – Jul 20
Safe Start (90%) ✓ Fits season (127 days to spare)
Transplant: Mar 25 🍅 Harvest: Jun 17 – Aug 12

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 Jackson County

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

Soil pH

Your soil pH (5.1–6.1) is more acidic than Soybeans prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Jackson County warms quickly in spring but drains fast. Soybeans will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Soybeans.

Organic Matter

Organic matter is moderate (2.2%). 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 269-day season

Sow every 9.1 weeks. Last sowing by Jul 29 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 5.3" 0" ❄️ Dormant
Feb 4.5" 0" ❄️ Dormant
Mar 4.3" 5.1" 0" ✅ Rainfall sufficient
Apr 4.3" 4.5" 0" ✅ Rainfall sufficient
May 4.3" 5.1" 0" ✅ Rainfall sufficient
Jun 4.3" 4.7" 0" ✅ Rainfall sufficient
Jul 4.3" 6.2" 0" ✅ Rainfall sufficient
Aug 4.3" 4.8" 0" ✅ Rainfall sufficient
Sep 4.3" 4.9" 0" ✅ Rainfall sufficient
Oct 4.3" 3.8" 0.5" 💧 Light watering
Nov 4.3" 4.4" 0" ✅ Rainfall sufficient
Dec 4.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Jackson 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 ~1,825 GDD — county provides 4,909 GDD Excellent fit

Soybeans Planting Timeline — Jackson County, MS

Soybeans Planting Calendar

Activity When Date Range
Direct Sow March 9 Mar 9 – Mar 30
Harvest June 1 Jun 1 – Jul 27

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

269 days in Jackson County

Growing Tips for Soybeans in Jackson County

Direct sow Soybeans outdoors after March 02 in Jackson County when soil has warmed and frost danger has passed.

Sandy soil in Jackson County dries quickly — mulch Soybeans with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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 Jackson County, MS?

Jackson County is in Zone 9a with an average last frost of March 2. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jackson County, MS?

Jackson County, Mississippi is in USDA Hardiness Zone 9a. The average last spring frost is March 2 and first fall frost is November 26.

🌱

Your Jackson County Garden Planner — Free

A 24-page printable planner built for Jackson County (Zone 9a). 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 Jackson County, MS. 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.