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When to Plant Soybeans in Hidalgo 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.

Hidalgo County, Texas is in USDA Zone 9b. The average last spring frost is February 6 and the first fall frost is December 18, giving you a growing season of approximately 315 days.

At an elevation of 4,081 feet, Hidalgo County receives approximately 67 inches of rainfall annually with predominantly loam soil. Summer highs average 100ยฐF, 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.

Hidalgo County, TX (Zone 9b) Year-round
315 days
Last Spring Frost February 6
315 growing days
First Fall Frost December 18

Hidalgo County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (188 days to spare)
Transplant: Jan 18 🍅 Harvest: Apr 12 – Jun 7
Recommended (50%) ✓ Fits season (175 days to spare)
Transplant: Feb 6 🍅 Harvest: May 1 – Jun 26
Safe Start (90%) ✓ Fits season (155 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 Hidalgo County

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

Soil pH

Your soil pH (6.2โ€“7.8) overlaps with Soybeans's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The loam soil in Hidalgo 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 315-day season

Sow every 9.1 weeks. Last sowing by Aug 20 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 308 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 โ€” 1.4" 0" โ„๏ธ Dormant
Feb 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Mar 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Apr 4.3" 6.7" 0" โœ… Rainfall sufficient
May 4.3" 10.1" 0" โœ… Rainfall sufficient
Jun 4.3" 9.4" 0" โœ… Rainfall sufficient
Jul 4.3" 9.3" 0" โœ… Rainfall sufficient
Aug 4.3" 8.7" 0" โœ… Rainfall sufficient
Sep 4.3" 6.9" 0" โœ… Rainfall sufficient
Oct 4.3" 4.5" 0" โœ… Rainfall sufficient
Nov 4.3" 2.5" 1.8" ๐Ÿ’ง Light watering
Dec 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering

Water needs are for active growing months only (Febโ€“Dec in Hidalgo 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 ~2,500 GDD — county provides 7,900 GDD Excellent fit

Soybeans Planting Timeline โ€” Hidalgo County, TX

Soybeans Planting Calendar

Activity When Date Range
Direct Sow February 13 Feb 13 โ€“ Mar 6
Harvest May 8 May 8 โ€“ Jul 3

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 Only during dry spells

๐Ÿ“… Days to Maturity

80โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 9b

๐Ÿ“† Growing Season

315 days in Hidalgo County

Growing Tips for Soybeans in Hidalgo County

Direct sow Soybeans outdoors after February 06 in Hidalgo County when soil has warmed and frost danger has passed.

With summer highs reaching 100ยฐF in Hidalgo 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 Hidalgo County, TX?

Hidalgo County is in Zone 9b with an average last frost of February 6. Plan your Soybeans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Hidalgo County, TX?

Hidalgo County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 6 and first fall frost is December 18.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Hidalgo County gardeners in Zone 9b 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 Hidalgo County, TX. Local conditions may vary. Last updated: April 2026.