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When to Plant Leeks in Harding County, SD

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.

Harding County, South Dakota is in USDA Zone 4b. The average last spring frost is May 16 and the first fall frost is September 22, giving you a growing season of approximately 129 days.

At an elevation of 750 feet, Harding County receives approximately 29.3 inches of rainfall annually with predominantly loam soil. Summer highs average 78°F, so choose short-season varieties of Leeks to ensure they mature before fall.

Harding County, SD (Zone 4b) Short season
129 days
Last Spring Frost May 16
129 growing days
First Fall Frost September 22

Harding County Soil Profile

Soil Type

Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Leeks Planting Timeline — Harding County, SD

Leeks Planting Calendar

Activity When Date Range
Start Indoors April 4 Apr 4 – Apr 18
Transplant Outdoors May 16 May 16 – May 30
Direct Sow May 9 May 9 – May 30
Harvest August 15 Aug 15 – Oct 10
Fall Sowing June 30 Jun 30 – Jul 14

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

Month-by-Month Timeline

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

📆 Growing Season

129 days in Harding County

Growing Tips for Harding 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 Harding County, SD?

Harding County is in Zone 4b with an average last frost of May 16. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.

What planting zone is Harding County, SD?

Harding County, South Dakota is in USDA Hardiness Zone 4b. The average last spring frost is May 16 and first fall frost is September 22.

🌱

Your Harding County Garden Planner — Free

A 22-page printable planner built for Harding 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 Harding County, SD. Local conditions may vary. Last updated: June 2026.

Sources & credits

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