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When to Plant Soybeans in Tom Green County, TX

Tom Green County, Texas Zone 8a May

This month in Tom Green County, Texas

Your Tom Green County, Texas garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost March 25
Avg. first frost November 12
Soil temp (4") 58°F
Watering High
Pest pressure Moderate
Daylight 13.6 hrs
Before June arrives, get these ready
  • 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.

Tom Green County, Texas is in USDA Zone 8a. The average last spring frost is March 25 and the first fall frost is November 12, giving you a growing season of approximately 232 days.

At an elevation of 4,366 feet, Tom Green County receives approximately 52.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 102°F, so Soybeans may need afternoon shade and extra watering during peak heat. 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.

Tom Green County, TX (Zone 8a) Long season
232 days
Last Spring Frost March 25
232 growing days
First Fall Frost November 12

Tom Green County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (96 days to spare)
Transplant: Mar 12 🍅 Harvest: Jun 4 – Jul 30
Recommended (50%) ✓ Fits season (92 days to spare)
Transplant: Mar 25 🍅 Harvest: Jun 17 – Aug 12
Safe Start (90%) ✓ Fits season (86 days to spare)
Transplant: Apr 14 🍅 Harvest: Jul 7 – Sep 1

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 Tom Green County

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

Soil pH

Your soil pH (7.2–8.3) is more alkaline than Soybeans prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Tom Green 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 low (0.9%). Add 2-3 inches of compost before planting Soybeans.

How to Plant Soybeans

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

Succession Planting Soybeans

3
successive plantings in your 232-day season

Sow every 9.1 weeks. Last sowing by Jul 15 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 875 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 3" 0" ❄️ Dormant
Feb 3.1" 0" ❄️ Dormant
Mar 4.3" 3.1" 1.2" 💧 Light watering
Apr 4.3" 1.5" 2.8" 🚿 Regular watering
May 4.3" 1.3" 3" 🚿 Regular watering
Jun 4.3" 1.9" 2.4" 🚿 Regular watering
Jul 4.3" 9.5" 0" ✅ Rainfall sufficient
Aug 4.3" 10.3" 0" ✅ Rainfall sufficient
Sep 4.3" 7.4" 0" ✅ Rainfall sufficient
Oct 4.3" 4.8" 0" ✅ Rainfall sufficient
Nov 4.3" 2.7" 1.6" 💧 Light watering
Dec 3.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Tom Green 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 ~2,650 GDD — county provides 6,148 GDD Excellent fit

Soybeans Planting Timeline — Tom Green County, TX

Soybeans Planting Calendar

Activity When Date Range
Direct Sow April 1 Apr 1 – Apr 22
Harvest June 24 Jun 24 – Aug 19

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 · 1-2 times/week

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 8a

📆 Growing Season

232 days in Tom Green County

Growing Tips for Soybeans in Tom Green County

Direct sow Soybeans outdoors after March 25 in Tom Green County when soil has warmed and frost danger has passed.

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

With summer highs reaching 102°F in Tom Green 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 Tom Green County, TX?

Tom Green County is in Zone 8a with an average last frost of March 25. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Tom Green County, TX?

Tom Green County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 25 and first fall frost is November 12.

🌱

Your Tom Green County Garden Planner — Free

A 24-page printable planner built for Tom Green 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 Tom Green 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.