Blog

When to plant Leeks in Shelby County, IA

Shelby County sits in USDA Zone 5a. Plant Leeks between April 16 (after last frost on April 30) and May 7. A second sowing from July 25 to August 8 extends the harvest into fall.

When to Plant Leeks in Shelby County, IA

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.

Shelby County, Iowa is in USDA Zone 5a. The average last spring frost is April 30 and the first fall frost is October 3, giving you a growing season of approximately 156 days.

At an elevation of 1,113 feet, Shelby County receives approximately 30.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Leeks during the growing season.

Shelby County, IA (Zone 5a) Moderate season
156 days
Last Spring Frost April 30
156 growing days
First Fall Frost October 3

Shelby County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Leeks Planting Timeline — Shelby County, IA

Leeks Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 – Apr 9
Transplant Outdoors April 30 Apr 30 – May 14
Direct Sow April 16 Apr 16 – May 7
Harvest July 30 Jul 30 – Oct 15
Fall Sowing July 25 Jul 25 – Aug 8

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June
July Fall Sowing 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 5a

📆 Growing Season

156 days in Shelby County

Growing Tips for Shelby 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 Shelby County, IA?

Shelby County is in Zone 5a with an average last frost of April 30. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.

What planting zone is Shelby County, IA?

Shelby County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 30 and first fall frost is October 3.

When should I plant Leeks in Shelby County, IA?

In Shelby County, IA, plant Leeks after the last frost (around April 30) and before the first frost (around October 3). Best results when soil holds above 50°F.

What growing zone is Shelby County, IA for Leeks?

Shelby County sits in USDA Zone 5a. Leeks grows reliably in zones 3a through 10b, so it's a good fit here.

Can Leeks grow in Shelby County's climate?

Yes — Leeks grows well in Shelby County's temperate climate. Shelby County averages a 156-day frost-free season, with last frost around April 30 and first frost around October 3.

🌱

Your Shelby County Garden Planner — Free

A 22-page printable planner built for Shelby County (Zone 5a). 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 Shelby County, IA. 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.