When to plant Leeks in Macomb County, MI
Aim to plant Leeks in Macomb County on or after April 14; the window stays open through May 5. Macomb County's 175-day frost-free season gives you a single solid spring crop with a brief fall option. A second sowing from August 11 to August 25 extends the harvest into fall.
When to Plant Leeks in Macomb County, MI
This month in Macomb County, Michigan
Here's what deserves your attention in Macomb County, Michigan this month. Everything below is tailored to Zone 6b and timed around your local frost dates.
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Start leeks under lights
Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.
Looking ahead to July
- First harvests: 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.
Macomb County, Michigan is in USDA Zone 6b. The average last spring frost is April 28 and the first fall frost is October 20, giving you a growing season of approximately 175 days.
At an elevation of 628 feet, Macomb County receives approximately 33.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Leeks during the growing season.
Macomb County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-6.9
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 Macomb County
How your county's soil matches Leeks's growing requirements.
Soil pH
Your soil pH (5.8–6.9) overlaps with Leeks's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Macomb County is excellent for Leeks — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.4%) — 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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | 3.5" | 3.8" | 0" | ✅ Rainfall sufficient |
| May | 3.5" | 3.7" | 0" | ✅ Rainfall sufficient |
| Jun | 3.5" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 4" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 3.5" | 0" | ✅ Rainfall sufficient |
| Sep | 3.5" | 2.7" | 0.8" | 💧 Light watering |
| Oct | 3.5" | 2.6" | 0.9" | 💧 Light watering |
| Nov | — | 2.3" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Macomb 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 — Macomb County, MI
Leeks Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 24 | Mar 24 – Apr 7 |
| Transplant Outdoors | April 28 | Apr 28 – May 12 |
| Direct Sow | April 14 | Apr 14 – May 5 |
| Harvest | July 28 | Jul 28 – Oct 13 |
| Fall Sowing | August 11 | Aug 11 – Aug 25 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| 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: acceptable
🗺️ USDA Zone
Zone 6b
📆 Growing Season
175 days in Macomb County
Growing Tips for Leeks in Macomb County
Direct sow Leeks outdoors after April 28 in Macomb County when soil has warmed and frost danger has passed.
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 Macomb County, MI?
Macomb County is in Zone 6b with an average last frost of April 28. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.
What planting zone is Macomb County, MI?
Macomb County, Michigan is in USDA Hardiness Zone 6b. The average last spring frost is April 28 and first fall frost is October 20.
When should I plant Leeks in Macomb County, MI?
In Macomb County, MI, plant Leeks after the last frost (around April 28) and before the first frost (around October 20). Best results when soil holds above 50°F.
What growing zone is Macomb County, MI for Leeks?
Macomb County sits in USDA Zone 6b. Leeks grows reliably in zones 3a through 10b, so it's a good fit here.
Can Leeks grow in Macomb County's climate?
Yes — Leeks grows well in Macomb County's temperate climate. Macomb County averages a 175-day frost-free season, with last frost around April 28 and first frost around October 20.
Your Macomb County Garden Planner — Free
A 22-page printable planner built for Macomb County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.