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When to plant Onion in Shingleton, MI

Plant Onion in Shingleton after May 10; the prime window is April 26–May 17. A second sowing from August 7 to August 21 extends the harvest into fall.

When to Plant Onion in Shingleton, MI

Alger County, Michigan Zone 5a June

Alger County, Michigan gardeners: here's your June plan

Each item below is timed to Alger County, Michigan's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 10
Avg. first frost October 16
Soil temp (4") 64°F
Watering Low
Pest pressure High
Daylight 15.6 hrs
  1. Start onion under lights

    These need a head start before your last frost (May 10). Sow into cells now so you're ready to transplant in a few weeks.

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Onions are a fundamental kitchen staple available in yellow, white, and red varieties. Choose long-day, short-day, or intermediate types based on your latitude.

Shingleton, Michigan is in USDA Zone 5a. The average last spring frost is May 10 and the first fall frost is October 16, giving you a growing season of approximately 159 days.

At an elevation of 1,014 feet, Alger County receives approximately 40.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Onion to ensure they mature before fall.

Shingleton, MI (Zone 5a) Moderate season
159 days
Last Spring Frost May 10
159 growing days
First Fall Frost October 16

Shingleton Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-7.1

Drainage

Well Drained

Onion Planting Risk Windows

Early Start (70% safe) ✓ Fits season (19 days to spare)
Start indoors: Mar 28 Transplant: May 2 🍅 Harvest: Aug 1 – Sep 19
Recommended (50%) ✓ Fits season (19 days to spare)
Start indoors: Apr 5 Transplant: May 10 🍅 Harvest: Aug 9 – Sep 27
Safe Start (90%) ✓ Fits season (21 days to spare)
Start indoors: Apr 20 Transplant: May 25 🍅 Harvest: Aug 24 – Oct 12

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 Shingleton

How your county's soil matches Onion's growing requirements.

Soil pH

Your soil pH (6.3–7.1) overlaps with Onion's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Onion.

Organic Matter

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

How to Plant Onion

1"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Onion Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 311 gal / 100 sq ft

Monthly Watering Guide for Onion

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

Month Onion Needs Rainfall You Supplement Action
Jan 2" 0" ❄️ Dormant
Feb 2" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 3.5" 0" ❄️ Dormant
May 4.3" 4.3" 0" ✅ Rainfall sufficient
Jun 4.3" 5" 0" ✅ Rainfall sufficient
Jul 4.3" 5" 0" ✅ Rainfall sufficient
Aug 4.3" 4.7" 0" ✅ Rainfall sufficient
Sep 4.3" 3.9" 0.4" 💧 Light watering
Oct 4.3" 3" 1.3" 💧 Light watering
Nov 2.9" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

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

Onion 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.

Onion needs ~1,050 GDD — county provides 1,590 GDD Excellent fit

Onion Planting Timeline — Shingleton, MI

Onion Planting Calendar

Activity When Date Range
Start Indoors April 5 Apr 5 – Apr 19
Transplant Outdoors May 10 May 10 – May 24
Direct Sow April 26 Apr 26 – May 17
Harvest August 9 Aug 9 – Sep 27
Fall Sowing August 7 Aug 7 – Aug 21

Plant 1" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June
July
August Fall Sowing 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 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

159 days in Alger County

Growing Tips for Onion in Shingleton

Direct sow Onion outdoors after May 10 in Alger County when soil has warmed and frost danger has passed.

Common pests for Onion in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 8-10 weeks before transplanting. Match day-length type to your latitude. Stop watering when tops begin to fall over and cure bulbs for 2-3 weeks before storage.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans
  • Asparagus

Check more plant combinations with our Companion Planting Checker →

When should I plant Onion in Shingleton, MI?

In Shingleton, MI, plant Onion after the last frost (around May 10) and before the first frost (around October 16). Best results when soil holds above 50°F.

What growing zone is Shingleton, MI for Onion?

Shingleton sits in USDA Zone 5a. Onion grows reliably in zones 3a through 10b, so it's a good fit here.

Can Onion grow in Shingleton's climate?

Yes — Onion grows well in Shingleton's temperate climate. Shingleton averages a 159-day frost-free season, with last frost around May 10 and first frost around October 16.

🌱

Your Alger County Garden Planner — Free

A 22-page printable planner built for Alger 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 Alger County, MI. Local conditions may vary. Last updated: June 2026.