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When to Plant Soybeans in Dillingham Census Area, AK

Soybeans (edamame) are a high-protein legume that fixes nitrogen in the soil. Fresh green soybeans harvested at the edamame stage are a nutritious snack.

Dillingham Census Area, Alaska is in USDA Zone 3a. The average last spring frost is May 1 and the first fall frost is September 6, giving you a growing season of approximately 128 days.

At an elevation of 410 feet, Dillingham Census Area receives approximately 54 inches of rainfall annually with predominantly silt loam soil. Summer highs average 60ยฐF, so choose short-season varieties of Soybeans to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Soybeans root diseases.

Dillingham Census Area, AK (Zone 3a) Short season
128 days
Last Spring Frost May 1
128 growing days
First Fall Frost September 6

Dillingham Census Area Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (57 days to spare)
Transplant: Apr 15 🍅 Harvest: Jul 8 – Aug 19
Recommended (50%) ✓ Fits season (57 days to spare)
Transplant: Apr 15 🍅 Harvest: Jul 8 – Aug 19
Safe Start (90%) ✓ Fits season (57 days to spare)
Transplant: Apr 15 🍅 Harvest: Jul 8 – Aug 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 Dillingham Census Area

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

Soil pH

Your soil pH (5.0โ€“6.2) is more acidic than Soybeans prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Dillingham Census Area is excellent for Soybeans โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Soybeans.

Organic Matter

Organic matter is excellent (6.6%) โ€” Soybeans will thrive.

How to Plant Soybeans

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

Plant Water Budget

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

Monthly Watering Guide for Soybeans

Soybeans needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Soybeans Needs Rainfall You Supplement Action
Jan โ€” 2.6" 0" โ„๏ธ Dormant
Feb โ€” 2.4" 0" โ„๏ธ Dormant
Mar โ€” 2.2" 0" โ„๏ธ Dormant
Apr โ€” 1.8" 0" โ„๏ธ Dormant
May 4.3" 2.3" 2" ๐Ÿ’ง Light watering
Jun 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Jul 4.3" 7.3" 0" โœ… Rainfall sufficient
Aug 4.3" 8.4" 0" โœ… Rainfall sufficient
Sep 4.3" 9.5" 0" โœ… Rainfall sufficient
Oct โ€” 6.5" 0" โ„๏ธ Dormant
Nov โ€” 4.2" 0" โ„๏ธ Dormant
Dec โ€” 3.3" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Dillingham Census Area). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Soybeans 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" โ€” every day above 50ยฐF 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.

Soybeans needs ~0 GDD — county provides 0 GDD May not mature

Soybeans Planting Timeline โ€” Dillingham Census Area, AK

Soybeans Planting Calendar

Activity When Date Range
Direct Sow May 15 May 15 โ€“ Jun 5
Harvest August 7 Aug 7 โ€“ Sep 18

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

80โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 3a

๐Ÿ“† Growing Season

128 days in Dillingham Census Area

Growing Tips for Soybeans in Dillingham Census Area

Your 128.0-day growing season in Dillingham Census Area is tight for Soybeans (80.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Soybeans 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 warms to 60F. Plant in blocks rather than rows for better pollination. Harvest for edamame when pods are plump and bright green.

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 Soybeans in Dillingham Census Area, AK?

Dillingham Census Area is in Zone 3a with an average last frost of May 1. Plan your Soybeans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Dillingham Census Area, AK?

Dillingham Census Area, Alaska is in USDA Hardiness Zone 3a. The average last spring frost is May 1 and first fall frost is September 6.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Dillingham Census Area gardeners in Zone 3a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Dillingham Census Area, AK. Local conditions may vary. Last updated: April 2026.