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When to Plant Yard Long Beans in St. Joseph County, MI

St. Joseph County, Michigan Zone 6a May

May to-do list for St. Joseph County, Michigan

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in St. Joseph County, Michigan.

Avg. last frost April 28
Avg. first frost October 16
Soil temp (4") 60°F
Watering Low
Pest pressure Low
Daylight 14.4 hrs
  1. Transplant yard long beans outside

    Your last frost (April 28) has passed. These warm-season crops can handle outdoor soil now.

  2. Sow yard long beans where they'll grow

    Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.

June prep starts now
  • Starting indoors: yard long beans

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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. Joseph County, Michigan is in USDA Zone 6a. The average last spring frost is April 28 and the first fall frost is October 16, giving you a growing season of approximately 171 days.

At an elevation of 564 feet, St. Joseph County receives approximately 39.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Yard Long Beans to ensure they mature before fall.

St. Joseph County, MI (Zone 6a) Moderate season
171 days
Last Spring Frost April 28
171 growing days
First Fall Frost October 16

St. Joseph County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (53 days to spare)
Start indoors: Mar 1 Transplant: May 10 🍅 Harvest: Jul 5 – Aug 16
Recommended (50%) ✓ Fits season (59 days to spare)
Start indoors: Mar 3 Transplant: May 12 🍅 Harvest: Jul 7 – Aug 18
Safe Start (90%) ✓ Fits season (53 days to spare)
Start indoors: Mar 20 Transplant: May 29 🍅 Harvest: Jul 24 – Sep 4

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. Joseph County

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

Soil pH

Your soil pH (5.8–6.7) overlaps with Yard Long Beans's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in St. Joseph County is excellent for Yard Long Beans — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.2%) — Yard Long Beans will thrive.

How to Plant Yard Long Beans

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

Succession Planting Yard Long Beans

3
successive plantings in your 171-day season

Sow every 6.3 weeks. Last sowing by Jul 28 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 45 gal / 100 sq ft

Monthly Watering Guide for Yard Long Beans

Yard Long Beans needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Yard Long Beans Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 5" 0" ✅ Rainfall sufficient
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.4" 0" ✅ Rainfall sufficient
Aug 4.3" 4.1" 0.2" 💧 Light watering
Sep 4.3" 3.5" 0.8" 💧 Light watering
Oct 4.3" 3" 1.3" 💧 Light watering
Nov 2.9" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in St. Joseph County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Yard Long Beans 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.

Yard Long Beans needs ~878 GDD — county provides 2,223 GDD Excellent fit

Yard Long Beans Planting Timeline — St. Joseph County, MI

Yard Long Beans Planting Calendar

Activity When Date Range
Start Indoors March 3 Mar 3 – Mar 17
Transplant Outdoors May 12 May 12 – May 26
Direct Sow May 5 May 5 – May 26
Harvest July 7 Jul 7 – Aug 18

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

55–80 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

171 days in St. Joseph County

Growing Tips for Yard Long Beans in St. Joseph County

Direct sow Yard Long Beans outdoors after April 28 in St. Joseph 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Yard Long Beans in St. Joseph County, MI?

St. Joseph County is in Zone 6a with an average last frost of April 28. Plan your Yard Long Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. Joseph County, MI?

St. Joseph County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is April 28 and first fall frost is October 16.

🌱

Your St. Joseph County Garden Planner — Free

A 24-page printable planner built for St. Joseph County (Zone 6a). 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 St. Joseph County, MI. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.