When to plant Leeks in Deerfield, IL
Deerfield's spring Leeks window runs April 7 through April 28. time plantings around the expected last-frost window for best survival. A second sowing from August 11 to August 25 extends the harvest into fall.
When to Plant Leeks in Deerfield, 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.
Deerfield, Illinois is in USDA Zone 6a. The average last spring frost is April 21 and the first fall frost is October 20, giving you a growing season of approximately 182 days.
At an elevation of 1,080 feet, Lake County receives approximately 33.5 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.
Deerfield Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-6.9
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 | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.3" | 1" | 💧 Light watering |
| May | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Jun | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 3.3" | 1" | 💧 Light watering |
| Aug | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Sep | 4.3" | 3.3" | 1" | 💧 Light watering |
| Oct | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Nov | — | 2.3" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Lake County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Leeks Planting Timeline — Deerfield, IL
Leeks Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 17 | Mar 17 – Mar 31 |
| Transplant Outdoors | April 21 | Apr 21 – May 5 |
| Direct Sow | April 7 | Apr 7 – Apr 28 |
| Harvest | July 21 | Jul 21 – Oct 6 |
| 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 | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors |
| 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 6a
📆 Growing Season
182 days in Lake County
Growing Tips for Deerfield
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
When should I plant Leeks in Deerfield, IL?
In Deerfield, IL, plant Leeks after the last frost (around April 21) and before the first frost (around October 20). Best results when soil holds above 50°F.
What growing zone is Deerfield, IL for Leeks?
Deerfield sits in USDA Zone 6a. Leeks grows reliably in zones 3a through 10b, so it's a good fit here.
Can Leeks grow in Deerfield's climate?
Yes — Leeks grows well in Deerfield's temperate climate. Deerfield averages a 182-day frost-free season, with last frost around April 21 and first frost around October 20.
Your Lake County Garden Planner — Free
A 22-page printable planner built for Lake County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.