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When to Plant Edamame in Harris County, TX

Harris County, Texas Zone 9b May

May in Harris County, Texas — your action list

Your garden in Harris County, Texas is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost February 14
Avg. first frost December 4
Soil temp (4") 77°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Pick edamame

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Coming up in June — start thinking about
  • 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.

Harris County, Texas is in USDA Zone 9b. The average last spring frost is February 14 and the first fall frost is December 4, giving you a growing season of approximately 293 days.

At an elevation of 390 feet, Harris County receives approximately 67.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 102°F, so Edamame may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Edamame will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Edamame root diseases.

Harris County, TX (Zone 9b) Year-round
293 days
Last Spring Frost February 14
293 growing days
First Fall Frost December 4

Harris County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.3-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (174 days to spare)
Transplant: Feb 6 🍅 Harvest: Apr 24 – Jun 5
Recommended (50%) ✓ Fits season (174 days to spare)
Transplant: Feb 14 🍅 Harvest: May 2 – Jun 13
Safe Start (90%) ✓ Fits season (170 days to spare)
Transplant: Mar 8 🍅 Harvest: May 24 – Jul 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 Harris County

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

Soil pH

Your soil pH (5.3–6.5) is more acidic than Edamame prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). 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 293-day season

Sow every 8.6 weeks. Last sowing by Aug 26 to harvest before frost.

Plant Water Budget

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

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 1.6" 0" ❄️ Dormant
Feb 3.9" 2.7" 1.2" 💧 Light watering
Mar 3.9" 3.8" 0.1" 💧 Light watering
Apr 3.9" 7.4" 0" ✅ Rainfall sufficient
May 3.9" 10.1" 0" ✅ Rainfall sufficient
Jun 3.9" 10" 0" ✅ Rainfall sufficient
Jul 3.9" 9.6" 0" ✅ Rainfall sufficient
Aug 3.9" 8.5" 0" ✅ Rainfall sufficient
Sep 3.9" 6.3" 0" ✅ Rainfall sufficient
Oct 3.9" 3.9" 0" ✅ Rainfall sufficient
Nov 3.9" 2.2" 1.7" 💧 Light watering
Dec 3.9" 1.6" 2.3" 🚿 Regular watering

Water needs are for active growing months only (Feb–Dec in Harris 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 ~2,319 GDD — county provides 7,791 GDD Excellent fit

Edamame Planting Timeline — Harris County, TX

Edamame Planting Calendar

Activity When Date Range
Direct Sow February 21 Feb 21 – Mar 14
Harvest May 9 May 9 – Jun 20

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

Month-by-Month Timeline

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

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_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

293 days in Harris County

Growing Tips for Edamame in Harris County

Direct sow Edamame outdoors after February 14 in Harris County when soil has warmed and frost danger has passed.

Sandy soil in Harris County dries quickly — mulch Edamame with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 102°F in Harris 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 Harris County, TX?

Harris County is in Zone 9b with an average last frost of February 14. Plan your Edamame planting based on this frost date — see the calendar above for exact timing.

What planting zone is Harris County, TX?

Harris County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 14 and first fall frost is December 4.

🌱

Your Harris County Garden Planner — Free

A 24-page printable planner built for Harris County (Zone 9b). 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 Harris 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.