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When to Plant Onion in Missaukee County, MI

Missaukee County, Michigan Zone 5a May

Your May planting checklist for Missaukee County, Michigan

A quick May briefing for Missaukee County, Michigan gardeners — what's urgent, what's next, and what can wait.

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. Move onion from tray to bed

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Outdoor sowing time: onion

    These tolerate cool soil, so you're not gambling by sowing now.

Before June arrives, get these ready
  • Starting indoors: onion

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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.

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 Onion 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
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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: Apr 9 Transplant: May 14 🍅 Harvest: Aug 13 – Oct 1
Recommended (50%) ✗ May not fit
Start indoors: Apr 14 Transplant: May 19 🍅 Harvest: Aug 18 – Oct 6
Safe Start (90%) ✗ May not fit
Start indoors: Apr 28 Transplant: Jun 2 🍅 Harvest: Sep 1 – Oct 20

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 Onion's growing requirements.

Soil pH

Your soil pH (6.3–7.0) is within Onion's preferred range (6.0–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.5%) — 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.

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 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 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.

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 ~1,522 GDD — county provides 1,943 GDD Good fit

Onion Planting Timeline — Missaukee County, MI

Onion Planting Calendar

Activity When Date Range
Start Indoors April 14 Apr 14 – Apr 28
Transplant Outdoors May 19 May 19 – Jun 2
Direct Sow May 5 May 5 – May 26
Harvest August 18 Aug 18 – Oct 6
Fall Sowing July 22 Jul 22 – Aug 5

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7 · Your soil: ideal

🗺️ USDA Zone

Zone 5a

📆 Growing Season

134 days in Missaukee County

Growing Tips for Onion in Missaukee County

Direct sow Onion outdoors after May 19 in Missaukee 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 →

Frequently Asked Questions

When should I plant Onion in Missaukee County, MI?

Missaukee County is in Zone 5a with an average last frost of May 19. Plan your Onion 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.