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When to Plant Edamame in Austin County, TX

Austin County, Texas Zone 9a May

May to-do list for Austin County, Texas

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Austin County, Texas.

Avg. last frost February 28
Avg. first frost November 29
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Bring in the edamame

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

To set up a strong June, finish these tasks
  • First harvests: edamame

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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.

Austin County, Texas is in USDA Zone 9a. The average last spring frost is February 28 and the first fall frost is November 29, giving you a growing season of approximately 274 days.

At an elevation of 350 feet, Austin County receives approximately 68.9 inches of rainfall annually with predominantly clay soil. Summer highs average 90°F, 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.

Austin County, TX (Zone 9a) Year-round
274 days
Last Spring Frost February 28
274 growing days
First Fall Frost November 29
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Austin County Soil Profile

Soil Type

Clay

Soil pH

6.8-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (156 days to spare)
Transplant: Feb 13 🍅 Harvest: May 1 – Jun 12
Recommended (50%) ✓ Fits season (155 days to spare)
Transplant: Feb 28 🍅 Harvest: May 16 – Jun 27
Safe Start (90%) ✓ Fits season (155 days to spare)
Transplant: Mar 22 🍅 Harvest: Jun 7 – Jul 19

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 Austin County

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

Soil pH

Your soil pH (6.8–8.1) is more alkaline than Edamame prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Heavy clay soil (41% clay) in Austin County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Organic Matter

Organic matter is moderate (3.2%). 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 274-day season

Sow every 8.6 weeks. Last sowing by Aug 21 to harvest before frost.

Plant Water Budget

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

Water stress score is 6/10 — 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 1.7" 0" ❄️ Dormant
Feb 3.9" 2.4" 1.5" 💧 Light watering
Mar 3.9" 4.3" 0" ✅ Rainfall sufficient
Apr 3.9" 7.2" 0" ✅ Rainfall sufficient
May 3.9" 9.6" 0" ✅ Rainfall sufficient
Jun 3.9" 11.9" 0" ✅ Rainfall sufficient
Jul 3.9" 8.5" 0" ✅ Rainfall sufficient
Aug 3.9" 9.2" 0" ✅ Rainfall sufficient
Sep 3.9" 5.7" 0" ✅ Rainfall sufficient
Oct 3.9" 4.6" 0" ✅ Rainfall sufficient
Nov 3.9" 2.2" 1.7" 💧 Light watering
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Austin County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~1,531 GDD — county provides 4,812 GDD Excellent fit

Edamame Planting Timeline — Austin County, TX

Edamame Planting Calendar

Activity When Date Range
Direct Sow March 7 Mar 7 – Mar 28
Harvest May 23 May 23 – Jul 4

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

Month-by-Month Timeline

MonthActivities
January
February
March Direct Sow
April
May Harvest
June Harvest
July Harvest
August
September
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · Natural rainfall sufficient

📅 Days to Maturity

75–100 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9a

📆 Growing Season

274 days in Austin County

Growing Tips for Edamame in Austin County

Direct sow Edamame outdoors after February 28 in Austin County when soil has warmed and frost danger has passed.

With Austin County's clay soil (41% clay), work in 3-4 inches of compost before planting Edamame. Avoid tilling when soil is wet to prevent compaction.

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 Austin County, TX?

Austin County is in Zone 9a with an average last frost of February 28. Plan your Edamame planting based on this frost date — see the calendar above for exact timing.

What planting zone is Austin County, TX?

Austin County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 28 and first fall frost is November 29.

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Your Austin County Garden Planner — Free

A 24-page printable planner built for Austin County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Austin County, TX. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.