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When to Plant Black Beans in Saginaw County, MI

Saginaw County, Michigan Zone 6a May

What to do in May

Here's what deserves your attention in Saginaw County, Michigan this month. Everything below is tailored to Zone 6a and timed around your local frost dates.

Avg. last frost April 30
Avg. first frost October 16
Soil temp (4") 57°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
  1. Scatter black beans into prepared beds

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

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Black beans are a warm-season legume producing small, dark, protein-rich beans that are a staple in Latin American and Caribbean cuisines.

Saginaw County, Michigan is in USDA Zone 6a. The average last spring frost is April 30 and the first fall frost is October 16, giving you a growing season of approximately 169 days.

At an elevation of 748 feet, Saginaw County receives approximately 39.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Black Beans during the growing season.

Saginaw County, MI (Zone 6a) Moderate season
169 days
Last Spring Frost April 30
169 growing days
First Fall Frost October 16

Saginaw 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 (22 days to spare)
Transplant: Apr 27 🍅 Harvest: Jul 27 – Sep 14
Recommended (50%) ✓ Fits season (29 days to spare)
Transplant: Apr 30 🍅 Harvest: Jul 30 – Sep 17
Safe Start (90%) ✓ Fits season (27 days to spare)
Transplant: May 16 🍅 Harvest: Aug 15 – Oct 3

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 Saginaw County

How your county's soil matches Black Beans's growing requirements.

Soil pH

Your soil pH (6.0–7.3) is within Black Beans's preferred range (6.0–7.5).

Soil Texture

The silt loam soil in Saginaw County is excellent for Black Beans — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.4%) — Black Beans will thrive.

How to Plant Black Beans

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

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 31 gal / 100 sq ft

Monthly Watering Guide for Black Beans

Black 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 Black Beans Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 4.3" 4" 0.3" 💧 Light watering
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 4" 0.3" 💧 Light watering
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 4.1" 0.2" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 3" 0" ❄️ Dormant
Dec 2.6" 0" ❄️ Dormant

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

Black 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.

Black Beans needs ~1,601 GDD — county provides 2,577 GDD Excellent fit

Black Beans Planting Timeline — Saginaw County, MI

Black Beans Planting Calendar

Activity When Date Range
Direct Sow May 7 May 7 – May 28
Harvest August 6 Aug 6 – Sep 24

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

169 days in Saginaw County

Growing Tips for Black Beans in Saginaw County

Direct sow Black Beans outdoors after April 30 in Saginaw County when soil has warmed and frost danger has passed.

Common pests for Black 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 last frost. Provide support for climbing varieties. Allow pods to dry fully on the vine before harvesting. Thresh dried pods by hand or in a pillowcase.

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 Black Beans in Saginaw County, MI?

Saginaw County is in Zone 6a with an average last frost of April 30. Plan your Black Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Saginaw County, MI?

Saginaw County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is April 30 and first fall frost is October 16.

🌱

Your Saginaw County Garden Planner — Free

A 24-page printable planner built for Saginaw 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 Saginaw 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.