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When to plant Leeks in Whiteside County, IL

For Leeks in Whiteside County, the safe spring window opens around April 2 and closes around April 23. Last expected frost is April 16, first fall frost October 16, giving a 183-day growing season. A second sowing from August 7 to August 21 extends the harvest into fall.

When to Plant Leeks in Whiteside County, IL

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.

Whiteside County, Illinois is in USDA Zone 5b. The average last spring frost is April 16 and the first fall frost is October 16, giving you a growing season of approximately 183 days.

At an elevation of 682 feet, Whiteside County receives approximately 30.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Leeks to ensure they mature before fall.

Whiteside County, IL (Zone 5b) Moderate season
183 days
Last Spring Frost April 16
183 growing days
First Fall Frost October 16

Whiteside County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Leeks Planting Timeline — Whiteside County, IL

Leeks Planting Calendar

Activity When Date Range
Start Indoors March 12 Mar 12 – Mar 26
Transplant Outdoors April 16 Apr 16 – Apr 30
Direct Sow April 2 Apr 2 – Apr 23
Harvest July 16 Jul 16 – Oct 1
Fall Sowing August 7 Aug 7 – Aug 21

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

Month-by-Month Timeline

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

183 days in Whiteside County

Growing Tips for Whiteside 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 Whiteside County, IL?

Whiteside County is in Zone 5b with an average last frost of April 16. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.

What planting zone is Whiteside County, IL?

Whiteside County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 16 and first fall frost is October 16.

When should I plant Leeks in Whiteside County, IL?

In Whiteside County, IL, plant Leeks after the last frost (around April 16) and before the first frost (around October 16). Best results when soil holds above 50°F.

What growing zone is Whiteside County, IL for Leeks?

Whiteside 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 Whiteside County's climate?

Yes — Leeks grows well in Whiteside County's temperate climate. Whiteside County averages a 183-day frost-free season, with last frost around April 16 and first frost around October 16.

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Your Whiteside County Garden Planner — Free

A 22-page printable planner built for Whiteside 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.

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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 Whiteside County, IL. Local conditions may vary. Last updated: August 2026.

Sources & credits

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