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When to Plant Edamame in McMullen County, TX

Edamame are soybeans harvested at the immature green stage for a sweet, nutty snack. They are high in protein and easy to grow in warm climates.

McMullen County, Texas is in USDA Zone 9a. The average last spring frost is February 20 and the first fall frost is December 1, giving you a growing season of approximately 284 days.

At an elevation of 3,741 feet, McMullen County receives approximately 58 inches of rainfall annually with predominantly loam soil. Summer highs average 103ยฐF, so Edamame may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Edamame root diseases.

McMullen County, TX (Zone 9a) Year-round
284 days
Last Spring Frost February 20
284 growing days
First Fall Frost December 1

McMullen County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (175 days to spare)
Transplant: Feb 3 🍅 Harvest: Apr 21 – Jun 2
Recommended (50%) ✓ Fits season (165 days to spare)
Transplant: Feb 20 🍅 Harvest: May 8 – Jun 19
Safe Start (90%) ✓ Fits season (158 days to spare)
Transplant: Mar 17 🍅 Harvest: Jun 2 – Jul 14

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 McMullen County

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

Soil pH

Your soil pH (6.8โ€“7.2) overlaps with Edamame's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Edamame.

How to Plant Edamame

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

Succession Planting Edamame

4
successive plantings in your 284-day season

Sow every 8.6 weeks. Last sowing by Aug 23 to harvest before frost.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 138 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Edamame

Edamame needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.

Month Edamame Needs Rainfall You Supplement Action
Jan โ€” 1.6" 0" โ„๏ธ Dormant
Feb 3.9" 2" 1.9" ๐Ÿ’ง Light watering
Mar 3.9" 3.7" 0.2" ๐Ÿ’ง Light watering
Apr 3.9" 6.4" 0" โœ… Rainfall sufficient
May 3.9" 9.4" 0" โœ… Rainfall sufficient
Jun 3.9" 9.8" 0" โœ… Rainfall sufficient
Jul 3.9" 7.3" 0" โœ… Rainfall sufficient
Aug 3.9" 6.5" 0" โœ… Rainfall sufficient
Sep 3.9" 4.6" 0" โœ… Rainfall sufficient
Oct 3.9" 3.5" 0.4" ๐Ÿ’ง Light watering
Nov 3.9" 1.7" 2.2" ๐Ÿšฟ Regular watering
Dec 3.9" 1.3" 2.6" ๐Ÿšฟ Regular watering

Water needs are for active growing months only (Febโ€“Dec in McMullen County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Edamame 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.

Edamame needs ~2,384 GDD — county provides 7,766 GDD Excellent fit

Edamame Planting Timeline โ€” McMullen County, TX

Edamame Planting Calendar

Activity When Date Range
Direct Sow February 27 Feb 27 โ€“ Mar 20
Harvest May 15 May 15 โ€“ Jun 26

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 โ€”
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.9"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

75โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

284 days in McMullen County

Growing Tips for Edamame in McMullen County

Direct sow Edamame outdoors after February 20 in McMullen County when soil has warmed and frost danger has passed.

With summer highs reaching 103ยฐF in McMullen County, provide afternoon shade for Edamame and water deeply in the morning.

Common pests for Edamame 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 is warm. Do not over-fertilize with nitrogen. Harvest when pods are plump and bright green but before they start to yellow. Steam or boil pods before eating.

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 Edamame in McMullen County, TX?

McMullen County is in Zone 9a with an average last frost of February 20. Plan your Edamame planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is McMullen County, TX?

McMullen County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 20 and first fall frost is December 1.

๐ŸŒฑ

Plan Your Garden with Confidence

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

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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 McMullen County, TX. Local conditions may vary. Last updated: April 2026.