Blog

When to Plant Soybeans in Edwards 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.

Edwards County, Texas is in USDA Zone 8a. The average last spring frost is April 2 and the first fall frost is November 8, giving you a growing season of approximately 220 days.

At an elevation of 4,265 feet, Edwards County receives approximately 61.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 102ยฐF, so Soybeans may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” 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.

Edwards County, TX (Zone 8a) Long season
220 days
Last Spring Frost April 2
220 growing days
First Fall Frost November 8

Edwards County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.8-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (83 days to spare)
Transplant: Mar 19 🍅 Harvest: Jun 11 – Aug 6
Recommended (50%) ✓ Fits season (80 days to spare)
Transplant: Apr 2 🍅 Harvest: Jun 25 – Aug 20
Safe Start (90%) ✓ Fits season (87 days to spare)
Transplant: Apr 18 🍅 Harvest: Jul 11 – Sep 5

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 Edwards County

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

Soil pH

Your soil pH (7.8โ€“8.1) is more alkaline than Soybeans prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is low (1.1%). 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 220-day season

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 8/10 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€” 4.5" 0" โ„๏ธ Dormant
Feb โ€” 3.3" 0" โ„๏ธ Dormant
Mar โ€” 3.3" 0" โ„๏ธ Dormant
Apr 4.3" 2" 2.3" ๐Ÿšฟ Regular watering
May 4.3" 1.3" 3" ๐Ÿšฟ Regular watering
Jun 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering
Jul 4.3" 11.5" 0" โœ… Rainfall sufficient
Aug 4.3" 13.8" 0" โœ… Rainfall sufficient
Sep 4.3" 7" 0" โœ… Rainfall sufficient
Oct 4.3" 4.9" 0" โœ… Rainfall sufficient
Nov 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Dec โ€” 4.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Nov in Edwards 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 ~2,650 GDD — county provides 5,830 GDD Excellent fit

Soybeans Planting Timeline โ€” Edwards County, TX

Soybeans Planting Calendar

Activity When Date Range
Direct Sow April 9 Apr 9 โ€“ Apr 30
Harvest July 2 Jul 2 โ€“ Aug 27

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

80โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

220 days in Edwards County

Growing Tips for Soybeans in Edwards County

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

Sandy soil in Edwards County dries quickly โ€” 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 102ยฐF in Edwards 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 Edwards County, TX?

Edwards County is in Zone 8a with an average last frost of April 2. Plan your Soybeans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Edwards County, TX?

Edwards County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is April 2 and first fall frost is November 8.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Edwards County gardeners in Zone 8a 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 Edwards County, TX. Local conditions may vary. Last updated: April 2026.