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When to Plant Lima Beans in Sanilac County, MI

Lima beans are a warm-season legume producing large, creamy beans with a buttery texture. Both bush and pole varieties are available, with pole types yielding more.

Sanilac County, Michigan is in USDA Zone 5b. The average last spring frost is May 4 and the first fall frost is October 17, giving you a growing season of approximately 166 days.

At an elevation of 985 feet, Sanilac County receives approximately 37 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Lima Beans during the growing season.

Sanilac County, MI (Zone 5b) Moderate season
166 days
Last Spring Frost May 4
166 growing days
First Fall Frost October 17

Sanilac County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (59 days to spare)
Transplant: Apr 29 🍅 Harvest: Jul 1 – Aug 12
Recommended (50%) ✓ Fits season (61 days to spare)
Transplant: May 4 🍅 Harvest: Jul 6 – Aug 17
Safe Start (90%) ✓ Fits season (57 days to spare)
Transplant: May 21 🍅 Harvest: Jul 23 – Sep 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 Sanilac County

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

Soil pH

Your soil pH (5.7โ€“7.0) overlaps with Lima Beans's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Sanilac County is excellent for Lima Beans โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (4.0%). Annual compost additions will help Lima Beans.

How to Plant Lima Beans

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

Succession Planting Lima Beans

3
successive plantings in your 166-day season

Sow every 6.9 weeks. Last sowing by Jul 19 to harvest before frost.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Lima Beans

Lima Beans needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.

Month Lima Beans Needs Rainfall You Supplement Action
Jan โ€” 1.3" 0" โ„๏ธ Dormant
Feb โ€” 1.7" 0" โ„๏ธ Dormant
Mar โ€” 2.5" 0" โ„๏ธ Dormant
Apr โ€” 3.9" 0" โ„๏ธ Dormant
May 3.9" 3.9" 0" โœ… Rainfall sufficient
Jun 3.9" 4.9" 0" โœ… Rainfall sufficient
Jul 3.9" 4.5" 0" โœ… Rainfall sufficient
Aug 3.9" 3.4" 0.5" ๐Ÿ’ง Light watering
Sep 3.9" 3.8" 0.1" ๐Ÿ’ง Light watering
Oct 3.9" 2.8" 1.1" ๐Ÿ’ง Light watering
Nov โ€” 2.3" 0" โ„๏ธ Dormant
Dec โ€” 2.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Sanilac County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Lima 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" โ€” every day above 50ยฐF 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.

Lima Beans needs ~1,088 GDD — county provides 2,407 GDD Excellent fit

Lima Beans Planting Timeline โ€” Sanilac County, MI

Lima Beans Planting Calendar

Activity When Date Range
Direct Sow May 11 May 11 โ€“ Jun 1
Harvest July 13 Jul 13 โ€“ Aug 24

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.9"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 5b

๐Ÿ“† Growing Season

166 days in Sanilac County

Growing Tips for Lima Beans in Sanilac County

Direct sow Lima Beans outdoors after May 04 in Sanilac County when soil has warmed and frost danger has passed.

Common pests for Lima 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 thoroughly warm at 65F or above. Do not soak seeds before planting as they may crack. Harvest when pods are plump but still green for fresh limas.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic
  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lima Beans in Sanilac County, MI?

Sanilac County is in Zone 5b with an average last frost of May 4. Plan your Lima Beans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Sanilac County, MI?

Sanilac County, Michigan is in USDA Hardiness Zone 5b. The average last spring frost is May 4 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Sanilac County gardeners in Zone 5b 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 Sanilac County, MI. Local conditions may vary. Last updated: April 2026.