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When to Plant Soybeans in Lee County, TX

Lee County, Texas Zone 9a May

May in the garden — Lee County, Texas

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

Avg. last frost February 28
Avg. first frost November 30
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Start harvesting soybeans

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Looking ahead to June
  • 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.

Lee County, Texas is in USDA Zone 9a. The average last spring frost is February 28 and the first fall frost is November 30, giving you a growing season of approximately 275 days.

At an elevation of 1,174 feet, Lee County receives approximately 59.1 inches of rainfall annually with predominantly clay soil. Summer highs average 97°F, so Soybeans may need afternoon shade and extra watering during peak heat. Clay soil retains moisture well for Soybeans, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Soybeans root diseases.

Lee County, TX (Zone 9a) Year-round
275 days
Last Spring Frost February 28
275 growing days
First Fall Frost November 30

Lee County Soil Profile

Soil Type

Clay

Soil pH

7.1-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (135 days to spare)
Transplant: Feb 14 🍅 Harvest: May 9 – Jul 4
Recommended (50%) ✓ Fits season (135 days to spare)
Transplant: Feb 28 🍅 Harvest: May 23 – Jul 18
Safe Start (90%) ✓ Fits season (128 days to spare)
Transplant: Mar 24 🍅 Harvest: Jun 16 – Aug 11

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 Lee County

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

Soil pH

Your soil pH (7.1–8.2) is more alkaline than Soybeans prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Your clay soil in Lee County is workable for Soybeans. Add compost annually to improve structure.

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Soybeans.

How to Plant Soybeans

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

Succession Planting Soybeans

4
successive plantings in your 275-day season

Sow every 9.1 weeks. Last sowing by Aug 02 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 247 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 1.6" 0" ❄️ Dormant
Feb 4.3" 1.8" 2.5" 🚿 Regular watering
Mar 4.3" 4.3" 0" ✅ Rainfall sufficient
Apr 4.3" 5.8" 0" ✅ Rainfall sufficient
May 4.3" 8.6" 0" ✅ Rainfall sufficient
Jun 4.3" 9.5" 0" ✅ Rainfall sufficient
Jul 4.3" 8.1" 0" ✅ Rainfall sufficient
Aug 4.3" 7.3" 0" ✅ Rainfall sufficient
Sep 4.3" 5.2" 0" ✅ Rainfall sufficient
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 4.3" 1.8" 2.5" 🚿 Regular watering
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Lee 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 ~2,275 GDD — county provides 6,279 GDD Excellent fit

Soybeans Planting Timeline — Lee County, TX

Soybeans Planting Calendar

Activity When Date Range
Direct Sow March 7 Mar 7 – Mar 28
Harvest May 30 May 30 – Jul 25

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

Month-by-Month Timeline

MonthActivities
January
February
March Direct Sow
April
May Harvest
June Harvest
July Harvest
August
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: too_alkaline

🗺️ USDA Zone

Zone 9a

📆 Growing Season

275 days in Lee County

Growing Tips for Soybeans in Lee County

Direct sow Soybeans outdoors after February 28 in Lee County when soil has warmed and frost danger has passed.

With Lee County's clay soil (37% clay), work in 3-4 inches of compost before planting Soybeans. Avoid tilling when soil is wet to prevent compaction.

With summer highs reaching 97°F in Lee County, provide afternoon shade for Soybeans and water deeply in the morning.

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 Lee County, TX?

Lee County is in Zone 9a with an average last frost of February 28. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lee County, TX?

Lee County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 28 and first fall frost is November 30.

🌱

Your Lee County Garden Planner — Free

A 24-page printable planner built for Lee 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 Lee County, TX. 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.