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When to Plant Edamame in Whatcom County, WA

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.

Whatcom County, Washington is in USDA Zone 7b. The average last spring frost is April 6 and the first fall frost is October 29, giving you a growing season of approximately 206 days.

At an elevation of 386 feet, Whatcom County receives approximately 49 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Edamame during the growing season.

Whatcom County, WA (Zone 7b) Long season
206 days
Last Spring Frost April 6
206 growing days
First Fall Frost October 29

Whatcom County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (90 days to spare)
Transplant: Mar 25 🍅 Harvest: Jun 10 – Jul 22
Recommended (50%) ✓ Fits season (87 days to spare)
Transplant: Apr 6 🍅 Harvest: Jun 22 – Aug 3
Safe Start (90%) ✓ Fits season (80 days to spare)
Transplant: May 6 🍅 Harvest: Jul 22 – Sep 2

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
1.0″/week
Watering frequency Only during dry spells
Season total 2 gal / 100 sq ft
Edamame needs ~1,203 GDD — county provides 2,832 GDD Excellent fit

Edamame Planting Timeline โ€” Whatcom County, WA

Edamame Planting Calendar

Activity When Date Range
Direct Sow April 13 Apr 13 โ€“ May 4
Harvest June 29 Jun 29 โ€“ Aug 10

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Direct Sow
May Direct Sow
June Harvest
July Harvest
August Harvest
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 7b

Growing Season

206 days

Growing Tips for Whatcom 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 Whatcom County, WA?

Whatcom County is in Zone 7b with an average last frost of April 6. Plan your Edamame planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Whatcom County, WA?

Whatcom County, Washington is in USDA Hardiness Zone 7b. The average last spring frost is April 6 and first fall frost is October 29.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Whatcom County gardeners in Zone 7b 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 Whatcom County, WA. Local conditions may vary. Last updated: April 2026.