When to plant Leeks in Mackinac County, MI
For Leeks in Mackinac County, the safe spring window opens around April 28 and closes around May 19. Last expected frost is May 12, first fall frost October 10, giving a 151-day growing season. A second sowing from August 1 to August 15 extends the harvest into fall.
When to Plant Leeks in Mackinac County, MI
July in the garden — Mackinac County, Michigan
Your garden in Mackinac County, Michigan is working on a schedule, even when you're not. Here's where you should be this July.
Coming up in August — start thinking about
- First harvests: leeks
- Fall sowing: 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.
Mackinac County, Michigan is in USDA Zone 5a. The average last spring frost is May 12 and the first fall frost is October 10, giving you a growing season of approximately 151 days.
At an elevation of 1,335 feet, Mackinac County receives approximately 35.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Leeks to ensure they mature before fall.
Mackinac County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-6.9
Drainage
Well Drained
Leeks Planting Risk Windows
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 Mackinac County
How your county's soil matches Leeks's growing requirements.
Soil pH
Your soil pH (6.2–6.9) is within Leeks's preferred range (6.0–7.0).
Soil Texture
The silt loam soil in Mackinac County is excellent for Leeks — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.1%) — Leeks will thrive.
How to Plant Leeks
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Leeks Water Budget
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 | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | — | 3.3" | 0" | ❄️ Dormant |
| May | 3.5" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jun | 3.5" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 4" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 3.6" | 0" | ✅ Rainfall sufficient |
| Sep | 3.5" | 2.8" | 0.7" | 💧 Light watering |
| Oct | 3.5" | 2.8" | 0.7" | 💧 Light watering |
| Nov | — | 2.7" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Mackinac 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 Planting Timeline — Mackinac County, MI
Leeks Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 7 | Apr 7 – Apr 21 |
| Transplant Outdoors | May 12 | May 12 – May 26 |
| Direct Sow | April 28 | Apr 28 – May 19 |
| Harvest | August 11 | Aug 11 – Oct 27 |
| Fall Sowing | August 1 | Aug 1 – Aug 15 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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 | — |
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
151 days in Mackinac County
Growing Tips for Leeks in Mackinac County
Direct sow Leeks outdoors after May 12 in Mackinac County when soil has warmed and frost danger has passed.
Your 151.0-day growing season in Mackinac 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
Check more plant combinations with our Companion Planting Checker →
Leeks in Other Locations
Frequently Asked Questions
When should I plant Leeks in Mackinac County, MI?
Mackinac County is in Zone 5a with an average last frost of May 12. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.
What planting zone is Mackinac County, MI?
Mackinac County, Michigan is in USDA Hardiness Zone 5a. The average last spring frost is May 12 and first fall frost is October 10.
When should I plant Leeks in Mackinac County, MI?
In Mackinac County, MI, plant Leeks after the last frost (around May 12) and before the first frost (around October 10). Best results when soil holds above 50°F.
What growing zone is Mackinac County, MI for Leeks?
Mackinac 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 Mackinac County's climate?
Yes — Leeks grows well in Mackinac County's temperate climate. Mackinac County averages a 151-day frost-free season, with last frost around May 12 and first frost around October 10.
Your Mackinac County Garden Planner — Free
A 22-page printable planner built for Mackinac 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.