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When to Plant Leeks in Adams County, WI

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.

Adams County, Wisconsin is in USDA Zone 4b. The average last spring frost is May 6 and the first fall frost is October 5, giving you a growing season of approximately 152 days.

At an elevation of 1,055 feet, Adams County receives approximately 41.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Leeks to ensure they mature before fall.

Adams County, WI (Zone 4b) Moderate season
152 days
Last Spring Frost May 6
152 growing days
First Fall Frost October 5

Adams County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Leeks Planting Timeline — Adams County, WI

Leeks Planting Calendar

Activity When Date Range
Start Indoors March 25 Mar 25 – Apr 8
Transplant Outdoors May 6 May 6 – May 20
Direct Sow April 29 Apr 29 – May 20
Harvest August 5 Aug 5 – Sep 30
Fall Sowing July 13 Jul 13 – Jul 27

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June
July Fall Sowing
August Harvest
September Harvest
October
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 4b

📆 Growing Season

152 days in Adams County

Growing Tips for Adams 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 Adams County, WI?

Adams County is in Zone 4b with an average last frost of May 6. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.

What planting zone is Adams County, WI?

Adams County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is May 6 and first fall frost is October 5.

🌱

Your Adams County Garden Planner — Free

A 22-page printable planner built for Adams County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Adams County, WI. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.