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When to plant Leeks in Marquette County County,

In Marquette County County, plant Leeks in spring between April 26 and May 17, once soil temps hold above 50°F. Marquette County County's last frost averages May 10, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between August 11 and August 25 — roughly 150 days before the first frost on October 20.

When to Plant Leeks in Marquette County, MI

Leeks
Marquette County, Michigan Zone 5a June

June to-do list for Marquette County, Michigan

We've pulled the most time-sensitive tasks for Marquette County, Michigan this June and put them front and centre. Tackle them in order.

Avg. last frost May 10
Avg. first frost October 20
Soil temp (4") 64°F
Watering Low
Pest pressure High
Daylight 15.6 hrs
  1. Indoor seed-starting week for leeks

    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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Leeks are a mild, sweet allium that produces long white shanks. They are more refined than onions and are a key ingredient in soups, stews, and gratins.

Marquette County, Michigan is in USDA Zone 5a. The average last spring frost is May 10 and the first fall frost is October 20, giving you a growing season of approximately 163 days.

At an elevation of 564 feet, Marquette County receives approximately 36.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Leeks to ensure they mature before fall.

Marquette County, MI (Zone 5a) Moderate season
163 days
Last Spring Frost May 10
163 growing days
First Fall Frost October 20
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Marquette County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.8

Drainage

Well Drained

Leeks Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 28 Transplant: May 2 🍅 Harvest: Aug 1 – Oct 17
Recommended (50%) ✗ May not fit
Start indoors: Apr 5 Transplant: May 10 🍅 Harvest: Aug 9 – Oct 25
Safe Start (90%) ✗ May not fit
Start indoors: Apr 22 Transplant: May 27 🍅 Harvest: Aug 26 – Nov 11

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 Marquette County

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

Soil pH

Your soil pH (6.0–6.8) is within Leeks's preferred range (6.0–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (5.1%) — Leeks will thrive.

How to Plant Leeks

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

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

Leeks Water Budget

Plant needs
0.8″/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 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Leeks

Leeks needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Leeks Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 4" 0" ❄️ Dormant
May 3.5" 4.5" 0" ✅ Rainfall sufficient
Jun 3.5" 4.3" 0" ✅ Rainfall sufficient
Jul 3.5" 3.6" 0" ✅ Rainfall sufficient
Aug 3.5" 3.4" 0.1" 💧 Light watering
Sep 3.5" 2.9" 0.6" 💧 Light watering
Oct 3.5" 3.2" 0.3" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

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

Leeks 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.

Leeks needs ~1,290 GDD — county provides 1,752 GDD Excellent fit

Leeks Planting Timeline — Marquette County, MI

Leeks 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 – Oct 25
Fall Sowing August 11 Aug 11 – Aug 25

Plant 1" deep · 15" apart · Rows 24" 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 Harvest
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Natural rainfall sufficient

📅 Days to Maturity

90–150 days

🧪 Soil pH

Needs 6–7 · Your soil: ideal

🗺️ USDA Zone

Zone 5a

📆 Growing Season

163 days in Marquette County

Growing Tips for Leeks in Marquette County

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

Your 163.0-day growing season in Marquette County is tight for Leeks (90.0-150.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Leeks 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 10-12 weeks before last frost. Transplant into trenches and hill soil around stems as they grow to increase the white portion. Harvest as needed.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Leeks in Marquette County, MI?

Marquette County is in Zone 5a with an average last frost of May 10. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.

What planting zone is Marquette County, MI?

Marquette County, Michigan is in USDA Hardiness Zone 5a. The average last spring frost is May 10 and first fall frost is October 20.

When should I plant Leeks in Marquette County County, ?

In Marquette County County, , plant Leeks after the last frost (around May 10) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Marquette County County, for Leeks?

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

Can Leeks grow in Marquette County County's climate?

Yes — Leeks grows well in Marquette County County's temperate climate. Marquette County County averages a 163-day frost-free season, with last frost around May 10 and first frost around October 20.

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Your Marquette County Garden Planner — Free

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.