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When to Plant Soybeans in Tulsa County, OK

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.

Tulsa County, Oklahoma is in USDA Zone 7a. The average last spring frost is April 7 and the first fall frost is October 26, giving you a growing season of approximately 202 days.

At an elevation of 752 feet, Tulsa County receives approximately 28.7 inches of rainfall annually with predominantly loam soil. Summer highs average 90ยฐF, providing good warmth for Soybeans during the growing season.

Tulsa County, OK (Zone 7a) Long season
202 days
Last Spring Frost April 7
202 growing days
First Fall Frost October 26

Tulsa County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (60 days to spare)
Transplant: Apr 2 🍅 Harvest: Jun 25 – Aug 20
Recommended (50%) ✓ Fits season (62 days to spare)
Transplant: Apr 7 🍅 Harvest: Jun 30 – Aug 25
Safe Start (90%) ✓ Fits season (62 days to spare)
Transplant: Apr 24 🍅 Harvest: Jul 17 – Sep 11

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
0.6″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 725 gal / 100 sq ft
Soybeans needs ~1,750 GDD — county provides 3,535 GDD Excellent fit

Soybeans Planting Timeline โ€” Tulsa County, OK

Soybeans Planting Calendar

Activity When Date Range
Direct Sow April 14 Apr 14 โ€“ May 5
Harvest July 7 Jul 7 โ€“ Sep 1

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 โ€”
July Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

80โ€“120 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 7a

Growing Season

202 days

Growing Tips for Tulsa County

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

Frequently Asked Questions

When should I plant Soybeans in Tulsa County, OK?

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

What planting zone is Tulsa County, OK?

Tulsa County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is April 7 and first fall frost is October 26.

๐ŸŒฑ

Plan Your Garden with Confidence

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