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When to plant Leeks in Roscommon County County,

Roscommon County County sits in USDA Zone 5a. Plant Leeks between May 1 (after last frost on May 15) and May 22. A second sowing from July 24 to August 7 extends the harvest into fall.

When to Plant Leeks in Roscommon County, MI

Leeks

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.

Roscommon County, Michigan is in USDA Zone 5a. The average last spring frost is May 15 and the first fall frost is October 2, giving you a growing season of approximately 140 days.

At an elevation of 1,298 feet, Roscommon County receives approximately 36 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Leeks to ensure they mature before fall.

Roscommon County, MI (Zone 5a) Short season
140 days
Last Spring Frost May 15
140 growing days
First Fall Frost October 2
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Roscommon County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.8

Drainage

Well Drained

Monthly Watering Guide for Leeks

Leeks needs approximately 1 inches of water per week (4.3" 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 1.6" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 3.5" 0" ❄️ Dormant
May 4.3" 4.3" 0" ✅ Rainfall sufficient
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.4" 0" ✅ Rainfall sufficient
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 3.2" 1.1" 💧 Light watering
Oct 4.3" 2.5" 1.8" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

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

Leeks Planting Timeline — Roscommon County, MI

Leeks Planting Calendar

Activity When Date Range
Start Indoors April 10 Apr 10 – Apr 24
Transplant Outdoors May 15 May 15 – May 29
Direct Sow May 1 May 1 – May 22
Harvest August 14 Aug 14 – Oct 30
Fall Sowing July 24 Jul 24 – Aug 7

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Transplant Outdoors Direct Sow
June
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

Moderate — regular watering

📅 Days to Maturity

90–150 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5a

📆 Growing Season

140 days in Roscommon County

Growing Tips for Roscommon County

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 Roscommon County, MI?

Roscommon County is in Zone 5a with an average last frost of May 15. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.

What planting zone is Roscommon County, MI?

Roscommon County, Michigan is in USDA Hardiness Zone 5a. The average last spring frost is May 15 and first fall frost is October 2.

When should I plant Leeks in Roscommon County County, ?

In Roscommon County County, , plant Leeks after the last frost (around May 15) and before the first frost (around October 2). Best results when soil holds above 50°F.

What growing zone is Roscommon County County, for Leeks?

Roscommon 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 Roscommon County County's climate?

Yes — Leeks grows well in Roscommon County County's temperate climate. Roscommon County County averages a 140-day frost-free season, with last frost around May 15 and first frost around October 2.

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Your Roscommon County Garden Planner — Free

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

Sources & credits

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