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When to Plant Soybeans in USDA Zone 5b

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.

In Zone 5b, the average last spring frost is around April 18 and the first fall frost is around October 13, giving you a growing season of approximately 178 days.

Zone 5b Moderate season
178 days
Last Spring Frost April 18
178 growing days
First Fall Frost October 13

Soybeans Planting Timeline — Zone 5b

Where Is USDA Zone 5b?

The map below highlights the states that contain Zone 5b. Click any state to see the Soybeans planting schedule for that location.

Prints a clean, ink-friendly version without maps or navigation.

Soybeans Planting Calendar — Zone 5b

Activity When Date Range
Direct Sow April 25 Apr 25 – May 16
Harvest July 18 Jul 18 – Sep 12

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

Month-by-Month Timeline

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

Free Zone 5b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 5b with start dates, transplant windows, and harvest times.

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Growing Conditions

Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

Days to Maturity

80–120 days

Soil pH

6 – 7

Zone Temperature Range

-15°F to -10°F average annual minimum

Growing Season

178 days (Zone 5b average)

Planting Specifications

Planting Depth1 inches
Plant Spacing15 inches apart
Row Spacing24 inches between rows

Succession Planting Soybeans in Zone 5b

2
successive plantings in Zone 5b's ~178-day season

Sow every 9.1 weeks for continuous harvest throughout the season.

Growing Tips for Soybeans in Zone 5b

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

Level Up Your Garden

Saving Soybeans Seeds

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Seed Starting Trays $8-20

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Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

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Garden Plant Markers $6-12

Keep your garden organized with durable, weather-resistant plant labels.

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Frequently Asked Questions

When should I plant Soybeans in Zone 5b?

In Zone 5b, plan your Soybeans planting around the average last frost date of April 18. Direct sow outdoors around April 25.

Can Soybeans grow in Zone 5b?

Yes, Soybeans can grow well in Zone 5b, hardy in USDA zones 3a through 10b. Zone 5b has a growing season of approximately 178 days, which is sufficient for Soybeans (80-120 days to maturity).

When can I harvest Soybeans in Zone 5b?

In Zone 5b, expect to harvest Soybeans from July 18 – September 12. Soybeans takes 80-120 days from planting to harvest.

What is the last frost date for Zone 5b?

The average last spring frost in Zone 5b is around April 18, and the first fall frost is around October 13. This gives a growing season of approximately 178 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Soybeans?

Good companion plants for Soybeans include Corn, Squash Summer, Potatoes. These companions can help with pest control, pollination, and nutrient sharing.

🌱

Plan Your Garden with Confidence

Get our free Garden Planner — organize your planting dates for Zone 5b, track your crops, and plan your garden season from seed to harvest.

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Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Planting dates are estimates based on average frost dates — local conditions may vary. Last updated: April 2026.