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When to Plant Edamame in Johnson 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.

Johnson County, Texas is in USDA Zone 8a. The average last spring frost is March 18 and the first fall frost is November 12, giving you a growing season of approximately 239 days.

At an elevation of 2,525 feet, Johnson County receives approximately 62.8 inches of rainfall annually with predominantly clay soil. Summer highs average 92ยฐF, providing good warmth for Edamame during the growing season. Clay soil retains moisture well for Edamame, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Edamame root diseases.

Johnson County, TX (Zone 8a) Long season
239 days
Last Spring Frost March 18
239 growing days
First Fall Frost November 12

Johnson County Soil Profile

Soil Type

Clay

Soil pH

7-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (128 days to spare)
Transplant: Mar 6 🍅 Harvest: May 22 – Jul 3
Recommended (50%) ✓ Fits season (120 days to spare)
Transplant: Mar 18 🍅 Harvest: Jun 3 – Jul 15
Safe Start (90%) ✓ Fits season (117 days to spare)
Transplant: Apr 12 🍅 Harvest: Jun 28 – Aug 9

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Edamame needs ~1,662 GDD — county provides 4,541 GDD Excellent fit

Edamame Planting Timeline โ€” Johnson County, TX

Edamame Planting Calendar

Activity When Date Range
Direct Sow March 25 Mar 25 โ€“ Apr 15
Harvest June 10 Jun 10 โ€“ Jul 22

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

75โ€“100 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 8a

Growing Season

239 days

Growing Tips for Johnson County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Edamame in Johnson County, TX?

Johnson County is in Zone 8a with an average last frost of March 18. Plan your Edamame planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Johnson County, TX?

Johnson County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 18 and first fall frost is November 12.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Johnson County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.

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