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When to Plant Sweet Potatoes in Missaukee County, MI

Missaukee County, Michigan Zone 5a May

Your May gardening checklist

Your Missaukee County, Michigan garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost May 19
Avg. first frost September 30
Soil temp (4") 58°F
Watering Moderate
Pest pressure Low
Daylight 14.6 hrs
  1. Scatter sweet potatoes into prepared beds

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

Get ahead of June
  • 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.

Missaukee County, Michigan is in USDA Zone 5a. The average last spring frost is May 19 and the first fall frost is September 30, giving you a growing season of approximately 134 days.

At an elevation of 667 feet, Missaukee County receives approximately 32.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Sweet Potatoes during the growing season.

Missaukee County, MI (Zone 5a) Short season
134 days
Last Spring Frost May 19
134 growing days
First Fall Frost September 30

Missaukee County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 19 Transplant: May 28 🍅 Harvest: Aug 27 – Oct 15
Recommended (50%) ✗ May not fit
Start indoors: Mar 24 Transplant: Jun 2 🍅 Harvest: Sep 1 – Oct 20
Safe Start (90%) ✗ May not fit
Start indoors: Apr 7 Transplant: Jun 16 🍅 Harvest: Sep 15 – Nov 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 Missaukee County

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

Soil pH

Your soil pH (6.3–7.0) is more alkaline than Sweet Potatoes prefers (5.5–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.5%) — 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
1.0″/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 1.5" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 3.4" 0" ❄️ Dormant
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 4" 0.3" 💧 Light watering
Jul 4.3" 3.3" 1" 💧 Light watering
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 2.5" 1.8" 💧 Light watering
Oct 2.7" 0" ❄️ Dormant
Nov 2.1" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Missaukee 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 ~1,522 GDD — county provides 1,943 GDD Good fit

Sweet Potatoes Planting Timeline — Missaukee County, MI

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors March 24 Mar 24 – Apr 7
Transplant Outdoors June 2 Jun 2 – Jun 16
Direct Sow May 26 May 26 – Jun 16
Harvest September 1 Sep 1 – Oct 20

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: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

134 days in Missaukee County

Growing Tips for Sweet Potatoes in Missaukee County

Direct sow Sweet Potatoes outdoors after May 19 in Missaukee County when soil has warmed and frost danger has passed.

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 Missaukee County, MI?

Missaukee County is in Zone 5a with an average last frost of May 19. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Missaukee County, MI?

Missaukee County, Michigan is in USDA Hardiness Zone 5a. The average last spring frost is May 19 and first fall frost is September 30.

🌱

Your Missaukee County Garden Planner — Free

A 24-page printable planner built for Missaukee 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.

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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 Missaukee 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.