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When to plant Leeks in Audubon County, IA

Plant Leeks in Audubon County from April 14 to May 5 in spring. Audubon County sits in USDA Zone 5a, with last frost around April 28 and first frost on October 3. A second sowing from July 25 to August 8 extends the harvest into fall.

When to Plant Leeks in Audubon 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.

Audubon County, Iowa is in USDA Zone 5a. The average last spring frost is April 28 and the first fall frost is October 3, giving you a growing season of approximately 158 days.

At an elevation of 1,056 feet, Audubon County receives approximately 32.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Leeks during the growing season.

Audubon County, IA (Zone 5a) Moderate season
158 days
Last Spring Frost April 28
158 growing days
First Fall Frost October 3

Audubon County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.8

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 1.3" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 3.7" 0.6" 💧 Light watering
Jul 4.3" 3.9" 0.4" 💧 Light watering
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 2.6" 1.7" 💧 Light watering
Oct 4.3" 2.6" 1.7" 💧 Light watering
Nov 2" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Audubon County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Leeks Planting Timeline — Audubon County, IA

Leeks Planting Calendar

Activity When Date Range
Start Indoors March 24 Mar 24 – Apr 7
Transplant Outdoors April 28 Apr 28 – May 12
Direct Sow April 14 Apr 14 – May 5
Harvest July 28 Jul 28 – Oct 13
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

158 days in Audubon County

Growing Tips for Audubon 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 Audubon County, IA?

Audubon County is in Zone 5a with an average last frost of April 28. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.

What planting zone is Audubon County, IA?

Audubon County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 28 and first fall frost is October 3.

When should I plant Leeks in Audubon County, IA?

In Audubon County, IA, plant Leeks after the last frost (around April 28) and before the first frost (around October 3). Best results when soil holds above 50°F.

What growing zone is Audubon County, IA for Leeks?

Audubon 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 Audubon County's climate?

Yes — Leeks grows well in Audubon County's temperate climate. Audubon County averages a 158-day frost-free season, with last frost around April 28 and first frost around October 3.

🌱

Your Audubon County Garden Planner — Free

A 22-page printable planner built for Audubon 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.

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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 Audubon County, IA. Local conditions may vary. Last updated: July 2026.

Sources & credits

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