Blog

When to Plant Soybeans in Webb County, TX

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.

Webb County, Texas is in USDA Zone 9a. The average last spring frost is February 9 and the first fall frost is December 9, giving you a growing season of approximately 303 days.

At an elevation of 3,543 feet, Webb County receives approximately 50.9 inches of rainfall annually with predominantly loam soil. Summer highs average 95ยฐF, so Soybeans may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Soybeans root diseases.

Webb County, TX (Zone 9a) Year-round
303 days
Last Spring Frost February 9
303 growing days
First Fall Frost December 9

Webb County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (177 days to spare)
Transplant: Jan 19 🍅 Harvest: Apr 13 – Jun 8
Recommended (50%) ✓ Fits season (163 days to spare)
Transplant: Feb 9 🍅 Harvest: May 4 – Jun 29
Safe Start (90%) ✓ Fits season (151 days to spare)
Transplant: Mar 5 🍅 Harvest: May 28 – Jul 23

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 Webb County

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

Soil pH

Your soil pH (6.6โ€“7.7) is more alkaline than Soybeans prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Webb County is excellent for Soybeans โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.3%). 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 303-day season

Sow every 9.1 weeks. Last sowing by Aug 11 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 964 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 1.3" 0" โ„๏ธ Dormant
Feb 4.3" 1.9" 2.4" ๐Ÿšฟ Regular watering
Mar 4.3" 2.8" 1.5" ๐Ÿ’ง Light watering
Apr 4.3" 5" 0" โœ… Rainfall sufficient
May 4.3" 8.3" 0" โœ… Rainfall sufficient
Jun 4.3" 7.6" 0" โœ… Rainfall sufficient
Jul 4.3" 5.9" 0" โœ… Rainfall sufficient
Aug 4.3" 6.4" 0" โœ… Rainfall sufficient
Sep 4.3" 5.2" 0" โœ… Rainfall sufficient
Oct 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Nov 4.3" 1.7" 2.6" ๐Ÿšฟ Regular watering
Dec 4.3" 1.5" 2.8" ๐Ÿšฟ Regular watering

Water needs are for active growing months only (Febโ€“Dec in Webb County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~2,125 GDD — county provides 6,460 GDD Excellent fit

Soybeans Planting Timeline โ€” Webb County, TX

Soybeans Planting Calendar

Activity When Date Range
Direct Sow February 16 Feb 16 โ€“ Mar 9
Harvest May 11 May 11 โ€“ Jul 6

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

80โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

303 days in Webb County

Growing Tips for Soybeans in Webb County

Direct sow Soybeans outdoors after February 09 in Webb 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 Webb County, TX?

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

What planting zone is Webb County, TX?

Webb County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 9 and first fall frost is December 9.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Webb County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Webb County, TX. Local conditions may vary. Last updated: April 2026.