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When to Plant Soybeans in Bethel Census Area, AK

Bethel Census Area, Alaska Zone 4a May

Your May gardening checklist

A quick May briefing for Bethel Census Area, Alaska gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 22
Avg. first frost September 21
Soil temp (4") 45°F
Watering High
Pest pressure Low
Daylight 17 hrs
To set up a strong June, finish these tasks
  • Direct-sowing: soybeans

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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.

Bethel Census Area, Alaska is in USDA Zone 4a. The average last spring frost is May 22 and the first fall frost is September 21, giving you a growing season of approximately 122 days.

At an elevation of 1,369 feet, Bethel Census Area receives approximately 50.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 70°F, 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.

Bethel Census Area, AK (Zone 4a) Short season
122 days
Last Spring Frost May 22
122 growing days
First Fall Frost September 21

Bethel Census Area Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 16 🍅 Harvest: Aug 8 – Oct 3
Recommended (50%) ✗ May not fit
Transplant: May 22 🍅 Harvest: Aug 14 – Oct 9
Safe Start (90%) ✗ May not fit
Transplant: Jun 3 🍅 Harvest: Aug 26 – Oct 21

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 Bethel Census Area

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

Soil pH

Your soil pH (5.2–6.3) is more acidic than Soybeans prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Bethel Census Area is excellent for Soybeans — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Soybeans.

Organic Matter

Organic matter is excellent (5.8%) — 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 2.6" 0" ❄️ Dormant
Feb 2" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 1.4" 0" ❄️ Dormant
May 4.3" 1.8" 2.5" 🚿 Regular watering
Jun 4.3" 4" 0.3" 💧 Light watering
Jul 4.3" 6.3" 0" ✅ Rainfall sufficient
Aug 4.3" 7.6" 0" ✅ Rainfall sufficient
Sep 4.3" 9.4" 0" ✅ Rainfall sufficient
Oct 6.7" 0" ❄️ Dormant
Nov 4.1" 0" ❄️ Dormant
Dec 2.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Bethel Census Area). Supplement amounts are based on average rainfall — 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" — 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.

Soybeans needs ~250 GDD — county provides 305 GDD Good fit

Soybeans Planting Timeline — Bethel Census Area, AK

Soybeans Planting Calendar

Activity When Date Range
Direct Sow June 5 Jun 5 – Jun 26
Harvest August 28 Aug 28 – Oct 23

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 4a

📆 Growing Season

122 days in Bethel Census Area

Growing Tips for Soybeans in Bethel Census Area

Direct sow Soybeans outdoors after May 22 in Bethel Census Area when soil has warmed and frost danger has passed.

Your 122.0-day growing season in Bethel 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 Bethel Census Area, AK?

Bethel Census Area is in Zone 4a with an average last frost of May 22. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bethel Census Area, AK?

Bethel Census Area, Alaska is in USDA Hardiness Zone 4a. The average last spring frost is May 22 and first fall frost is September 21.

🌱

Your Bethel Census Area Garden Planner — Free

A 24-page printable planner built for Bethel Census Area (Zone 4a). 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 Bethel Census Area, AK. Local conditions may vary. Last updated: May 2026.

Sources & credits

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