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

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, Missouri is in USDA Zone 6a. The average last spring frost is April 8 and the first fall frost is October 26, giving you a growing season of approximately 201 days.

At an elevation of 699 feet, St. Clair County receives approximately 41.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Yard Long Beans during the growing season.

St. Clair County, MO (Zone 6a) Long season
201 days
Last Spring Frost April 8
201 growing days
First Fall Frost October 26

St. Clair County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (89 days to spare)
Start indoors: Feb 4 Transplant: Apr 15 🍅 Harvest: Jun 10 – Jul 22
Recommended (50%) ✓ Fits season (89 days to spare)
Start indoors: Feb 11 Transplant: Apr 22 🍅 Harvest: Jun 17 – Jul 29
Safe Start (90%) ✓ Fits season (89 days to spare)
Start indoors: Feb 22 Transplant: May 3 🍅 Harvest: Jun 28 – Aug 9

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 St. Clair County

How your county's soil matches Yard Long Beans's growing requirements.

Soil pH

Your soil pH (5.5โ€“6.7) overlaps with Yard Long Beans's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

The silt loam soil in St. Clair County is excellent for Yard Long Beans โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Yard Long Beans.

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Yard Long Beans.

How to Plant Yard Long Beans

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

Succession Planting Yard Long Beans

4
successive plantings in your 201-day season

Sow every 6.3 weeks. Last sowing by Aug 07 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Yard Long Beans needs ~1,181 GDD — county provides 3,517 GDD Excellent fit

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

Yard Long Beans Planting Calendar

Activity When Date Range
Start Indoors February 11 Feb 11 โ€“ Feb 25
Transplant Outdoors April 22 Apr 22 โ€“ May 6
Direct Sow April 15 Apr 15 โ€“ May 6
Harvest June 17 Jun 17 โ€“ Jul 29

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 Transplant Outdoors Direct Sow
June Harvest
July Harvest
August โ€”
September โ€”
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

55โ€“80 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

201 days in St. Clair County

Growing Tips for Yard Long Beans in St. Clair County

Direct sow Yard Long Beans outdoors after April 08 in St. Clair County when soil has warmed and frost danger has passed.

Common pests for Yard Long Beans 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 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, MO?

St. Clair County is in Zone 6a with an average last frost of April 8. 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, MO?

St. Clair County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 8 and first fall frost is October 26.

๐ŸŒฑ

Plan Your Garden with Confidence

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