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When to Plant Edamame in St. Martin Parish, LA

St. Martin Parish, Louisiana Zone 9a May

Top priorities for St. Martin Parish, Louisiana gardeners in May

We've pulled the most time-sensitive tasks for St. Martin Parish, Louisiana this May and put them front and centre. Tackle them in order.

Avg. last frost February 13
Avg. first frost December 5
Soil temp (4") 75°F
Watering Moderate
Pest pressure High
Daylight 13.5 hrs
  1. Harvest edamame as they ripen

    If you can't use it all right away, check the food-preservation section of your planner.

June will be here before you know it — start on
  • 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.

St. Martin Parish, Louisiana is in USDA Zone 9a. The average last spring frost is February 13 and the first fall frost is December 5, giving you a growing season of approximately 295 days.

At an elevation of 417 feet, St. Martin Parish receives approximately 55.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°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.

St. Martin Parish, LA (Zone 9a) Year-round
295 days
Last Spring Frost February 13
295 growing days
First Fall Frost December 5

St. Martin Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

5.2-6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (180 days to spare)
Transplant: Jan 31 🍅 Harvest: Apr 18 – May 30
Recommended (50%) ✓ Fits season (176 days to spare)
Transplant: Feb 13 🍅 Harvest: May 1 – Jun 12
Safe Start (90%) ✓ Fits season (166 days to spare)
Transplant: Mar 9 🍅 Harvest: May 25 – Jul 6

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 St. Martin Parish

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

Soil pH

Your soil pH (5.2–6.0) is more acidic than Edamame prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Edamame.

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 295-day season

Sow every 8.6 weeks. Last sowing by Aug 27 to harvest before frost.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.8″/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 5.1" 0" ❄️ Dormant
Feb 3.9" 4.4" 0" ✅ Rainfall sufficient
Mar 3.9" 5.7" 0" ✅ Rainfall sufficient
Apr 3.9" 3.8" 0.1" 💧 Light watering
May 3.9" 3.7" 0.2" 💧 Light watering
Jun 3.9" 5.1" 0" ✅ Rainfall sufficient
Jul 3.9" 6.4" 0" ✅ Rainfall sufficient
Aug 3.9" 5.6" 0" ✅ Rainfall sufficient
Sep 3.9" 3.8" 0.1" 💧 Light watering
Oct 3.9" 3.3" 0.6" 💧 Light watering
Nov 3.9" 4.4" 0" ✅ Rainfall sufficient
Dec 3.9" 4.1" 0" ✅ Rainfall sufficient

Water needs are for active growing months only (Feb–Dec in St. Martin Parish). 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 ~1,925 GDD — county provides 6,512 GDD Excellent fit

Edamame Planting Timeline — St. Martin Parish, LA

Edamame Planting Calendar

Activity When Date Range
Direct Sow February 20 Feb 20 – Mar 13
Harvest May 8 May 8 – Jun 19

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 9a

📆 Growing Season

295 days in St. Martin Parish

Growing Tips for Edamame in St. Martin Parish

Direct sow Edamame outdoors after February 13 in St. Martin Parish when soil has warmed and frost danger has passed.

Sandy soil in St. Martin Parish 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 96°F in St. Martin Parish, 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 St. Martin Parish, LA?

St. Martin Parish is in Zone 9a with an average last frost of February 13. Plan your Edamame planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. Martin Parish, LA?

St. Martin Parish, Louisiana is in USDA Hardiness Zone 9a. The average last spring frost is February 13 and first fall frost is December 5.

🌱

Your St. Martin Parish Garden Planner — Free

A 24-page printable planner built for St. Martin Parish (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 St. Martin Parish, LA. 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.