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When to Plant Yard Long Beans in St. Clair County, IL

Yard long beans are a tropical legume that produces slender pods up to 24 inches long. They are a staple in Southeast Asian cooking and thrive in hot weather.

St. Clair County, Illinois is in USDA Zone 6b. The average last spring frost is April 2 and the first fall frost is November 2, giving you a growing season of approximately 214 days.

At an elevation of 711 feet, St. Clair County receives approximately 34.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Yard Long Beans during the growing season.

St. Clair County, IL (Zone 6b) Long season
214 days
Last Spring Frost April 2
214 growing days
First Fall Frost November 2

St. Clair County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (104 days to spare)
Start indoors: Jan 29 Transplant: Apr 9 🍅 Harvest: Jun 4 – Jul 16
Recommended (50%) ✓ Fits season (102 days to spare)
Start indoors: Feb 5 Transplant: Apr 16 🍅 Harvest: Jun 11 – Jul 23
Safe Start (90%) ✓ Fits season (108 days to spare)
Start indoors: Feb 20 Transplant: May 1 🍅 Harvest: Jun 26 – Aug 7

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
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 756 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Yard Long Beans needs ~1,131 GDD — county provides 3,584 GDD Excellent fit

Yard Long Beans Planting Timeline โ€” St. Clair County, IL

Yard Long Beans Planting Calendar

Activity When Date Range
Start Indoors February 5 Feb 5 โ€“ Feb 19
Transplant Outdoors April 16 Apr 16 โ€“ Apr 30
Direct Sow April 9 Apr 9 โ€“ Apr 30
Harvest June 11 Jun 11 โ€“ Jul 23

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

55โ€“80 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 6b

Growing Season

214 days

Growing Tips for St. Clair County

Direct sow after soil is warm. Provide tall poles or trellising as vines can reach 8-10 feet. Harvest when pods are pencil-thick before seeds bulge. Cook quickly for best texture.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Level Up Your Garden

Frequently Asked Questions

When should I plant Yard Long Beans in St. Clair County, IL?

St. Clair County is in Zone 6b with an average last frost of April 2. Plan your Yard Long Beans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is St. Clair County, IL?

St. Clair County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 2 and first fall frost is November 2.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help St. Clair County gardeners in Zone 6b 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 St. Clair County, IL. Local conditions may vary. Last updated: April 2026.