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When to Plant Sweet Potatoes in Crawford County, MI

Crawford County, Michigan Zone 5a May

Your May gardening checklist

Your garden in Crawford County, Michigan is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost May 22
Avg. first frost September 29
Soil temp (4") 56°F
Watering Low
Pest pressure Low
Daylight 14.6 hrs
  1. Put sweet potatoes seeds straight in the ground

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

To set up a strong June, finish these tasks
  • Transplants going out: sweet potatoes

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Sweet potatoes are a warm-season root crop that produces nutritious, sweet tubers in orange, white, and purple varieties. They need a long, hot growing season.

Crawford County, Michigan is in USDA Zone 5a. The average last spring frost is May 22 and the first fall frost is September 29, giving you a growing season of approximately 130 days.

At an elevation of 894 feet, Crawford County receives approximately 34.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Sweet Potatoes to ensure they mature before fall.

Crawford County, MI (Zone 5a) Short season
130 days
Last Spring Frost May 22
130 growing days
First Fall Frost September 29

Crawford County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 23 Transplant: Jun 1 🍅 Harvest: Aug 31 – Oct 19
Recommended (50%) ✗ May not fit
Start indoors: Mar 27 Transplant: Jun 5 🍅 Harvest: Sep 4 – Oct 23
Safe Start (90%) ✗ May not fit
Start indoors: Apr 8 Transplant: Jun 17 🍅 Harvest: Sep 16 – Nov 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 Crawford County

How your county's soil matches Sweet Potatoes's growing requirements.

Soil pH

Your soil pH (5.9–7.0) overlaps with Sweet Potatoes's range (5.5–6.5), though not a perfect match.

Soil Texture

The silt loam soil in Crawford County is excellent for Sweet Potatoes — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.8%) — Sweet Potatoes will thrive.

How to Plant Sweet Potatoes

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

Plant Water Budget

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

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Sweet Potatoes

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

Month Sweet Potatoes Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 3" 0" ❄️ Dormant
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 4.2" 0.1" 💧 Light watering
Jul 4.3" 3.8" 0.5" 💧 Light watering
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 2.8" 1.5" 💧 Light watering
Oct 2.6" 0" ❄️ Dormant
Nov 2.2" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

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

Sweet Potatoes 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.

Sweet Potatoes needs ~1,129 GDD — county provides 1,397 GDD Good fit

Sweet Potatoes Planting Timeline — Crawford County, MI

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors March 27 Mar 27 – Apr 10
Transplant Outdoors June 5 Jun 5 – Jun 19
Direct Sow May 29 May 29 – Jun 19
Harvest September 4 Sep 4 – Oct 23

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

130 days in Crawford County

Growing Tips for Sweet Potatoes in Crawford County

Direct sow Sweet Potatoes outdoors after May 22 in Crawford County when soil has warmed and frost danger has passed.

Your 130.0-day growing season in Crawford County is tight for Sweet Potatoes (90.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Plant slips (rooted sprouts) after soil is thoroughly warm. Build raised mounds for better root development. Cure harvested roots at 80-85F for 10 days to develop sweetness.

Companion Planting

Good Companions

Avoid Planting Near

  • Squash Summer

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sweet Potatoes in Crawford County, MI?

Crawford County is in Zone 5a with an average last frost of May 22. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Crawford County, MI?

Crawford County, Michigan is in USDA Hardiness Zone 5a. The average last spring frost is May 22 and first fall frost is September 29.

🌱

Your Crawford County Garden Planner — Free

A 24-page printable planner built for Crawford County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Crawford County, MI. Local conditions may vary. Last updated: May 2026.

Sources & credits

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