When to plant Leeks in Winnebago County, IL
For Winnebago County, gardeners: plant Leeks April 12 through May 3 once soil reads 50°F. A second sowing from August 3 to August 17 extends the harvest into fall.
When to Plant Leeks in Winnebago County, IL
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.
Winnebago County, Illinois is in USDA Zone 5b. The average last spring frost is April 26 and the first fall frost is October 12, giving you a growing season of approximately 169 days.
At an elevation of 1,318 feet, Winnebago County receives approximately 38.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Leeks during the growing season.
Winnebago County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Leeks Planting Timeline — Winnebago County, IL
Leeks Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 22 | Mar 22 – Apr 5 |
| Transplant Outdoors | April 26 | Apr 26 – May 10 |
| Direct Sow | April 12 | Apr 12 – May 3 |
| Harvest | July 26 | Jul 26 – Oct 11 |
| Fall Sowing | August 3 | Aug 3 – Aug 17 |
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
Moderate — regular watering
📅 Days to Maturity
90–150 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 5b
📆 Growing Season
169 days in Winnebago County
Growing Tips for Winnebago 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
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Leeks in Other Locations
Frequently Asked Questions
When should I plant Leeks in Winnebago County, IL?
Winnebago County is in Zone 5b with an average last frost of April 26. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.
What planting zone is Winnebago County, IL?
Winnebago County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 26 and first fall frost is October 12.
When should I plant Leeks in Winnebago County, IL?
In Winnebago County, IL, plant Leeks after the last frost (around April 26) and before the first frost (around October 12). Best results when soil holds above 50°F.
What growing zone is Winnebago County, IL for Leeks?
Winnebago County sits in USDA Zone 5b. Leeks grows reliably in zones 3a through 10b, so it's a good fit here.
Can Leeks grow in Winnebago County's climate?
Yes — Leeks grows well in Winnebago County's temperate climate. Winnebago County averages a 169-day frost-free season, with last frost around April 26 and first frost around October 12.
Your Winnebago County Garden Planner — Free
A 22-page printable planner built for Winnebago County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.