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When to Plant Edamame in Wallowa County, OR

Wallowa County, Oregon Zone 6b May

May to-do list for Wallowa County, Oregon

Welcome to May in Zone 6b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 11
Avg. first frost September 22
Soil temp (4") 57°F
Watering High
Pest pressure Low
Daylight 14.7 hrs
  1. Scatter edamame into prepared beds

    Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.

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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.

Wallowa County, Oregon is in USDA Zone 6b. The average last spring frost is May 11 and the first fall frost is September 22, giving you a growing season of approximately 134 days.

At an elevation of 1,240 feet, Wallowa County receives approximately 22.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Edamame during the growing season.

Wallowa County, OR (Zone 6b) Short season
134 days
Last Spring Frost May 11
134 growing days
First Fall Frost September 22
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Wallowa County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (13 days to spare)
Transplant: May 1 🍅 Harvest: Jul 17 – Aug 28
Recommended (50%) ✓ Fits season (15 days to spare)
Transplant: May 11 🍅 Harvest: Jul 27 – Sep 7
Safe Start (90%) ✓ Fits season (20 days to spare)
Transplant: Jun 12 🍅 Harvest: Aug 28 – Oct 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.

Soil Compatibility in Wallowa County

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

Soil pH

Your soil pH (5.3–6.2) is more acidic than Edamame prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Wallowa County is excellent for Edamame — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Edamame.

Organic Matter

Organic matter is excellent (5.4%) — Edamame will thrive.

How to Plant Edamame

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

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.7″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 551 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 2.9" 0" ❄️ Dormant
Feb 2.3" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 3.9" 1.3" 2.6" 🚿 Regular watering
Jun 3.9" 1" 2.9" 🚿 Regular watering
Jul 3.9" 0.4" 3.5" 🚿 Regular watering
Aug 3.9" 0.4" 3.5" 🚿 Regular watering
Sep 3.9" 1" 2.9" 🚿 Regular watering
Oct 2.1" 0" ❄️ Dormant
Nov 3.9" 0" ❄️ Dormant
Dec 3.6" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Wallowa 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 ~1,203 GDD — county provides 1,842 GDD Excellent fit

Edamame Planting Timeline — Wallowa County, OR

Edamame Planting Calendar

Activity When Date Range
Direct Sow May 18 May 18 – Jun 8
Harvest August 3 Aug 3 – Sep 14

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · 1-2 times/week

📅 Days to Maturity

75–100 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

134 days in Wallowa County

Growing Tips for Edamame in Wallowa County

Direct sow Edamame outdoors after May 11 in Wallowa County when soil has warmed and frost danger has passed.

Common pests for Edamame in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

Wallowa County receives only 23" of rain annually. Edamame needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Wallowa County, OR?

Wallowa County is in Zone 6b with an average last frost of May 11. Plan your Edamame planting based on this frost date — see the calendar above for exact timing.

What planting zone is Wallowa County, OR?

Wallowa County, Oregon is in USDA Hardiness Zone 6b. The average last spring frost is May 11 and first fall frost is September 22.

🌱

Your Wallowa County Garden Planner — Free

A 24-page printable planner built for Wallowa County (Zone 6b). 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 Wallowa County, OR. 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.