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When to Plant Leeks in Hutchinson County, SD

Hutchinson County, South Dakota Zone 5a May

What to do in May

May is a pivotal month for Hutchinson County, South Dakota gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 1
Avg. first frost October 6
Soil temp (4") 56°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
  1. Time to transplant leeks

    Frost risk is low now in Hutchinson County, South Dakota. If you've been covering beds overnight, you can stop.

Before June arrives, get these ready
  • Starting indoors: leeks

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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.

Hutchinson County, South Dakota is in USDA Zone 5a. The average last spring frost is May 1 and the first fall frost is October 6, giving you a growing season of approximately 158 days.

At an elevation of 1,008 feet, Hutchinson County receives approximately 32.1 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Leeks to ensure they mature before fall.

Hutchinson County, SD (Zone 5a) Moderate season
158 days
Last Spring Frost May 1
158 growing days
First Fall Frost October 6

Hutchinson County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 20 Transplant: Apr 24 🍅 Harvest: Jul 24 – Oct 9
Recommended (50%) ✗ May not fit
Start indoors: Mar 27 Transplant: May 1 🍅 Harvest: Jul 31 – Oct 16
Safe Start (90%) ✗ May not fit
Start indoors: Apr 9 Transplant: May 14 🍅 Harvest: Aug 13 – Oct 29

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Hutchinson County

How your county's soil matches Leeks's growing requirements.

Soil pH

Your soil pH (6.5–7.2) overlaps with Leeks's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in Hutchinson County is excellent for Leeks — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Leeks.

Organic Matter

Organic matter is moderate (3.4%). Annual compost additions will help Leeks.

How to Plant Leeks

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.9″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 263 gal / 100 sq ft

Monthly Watering Guide for Leeks

Leeks needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Leeks Needs Rainfall You Supplement Action
Jan 0.8" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 3" 0" ❄️ Dormant
May 3.5" 5.3" 0" ✅ Rainfall sufficient
Jun 3.5" 4.3" 0" ✅ Rainfall sufficient
Jul 3.5" 4" 0" ✅ Rainfall sufficient
Aug 3.5" 4.2" 0" ✅ Rainfall sufficient
Sep 3.5" 3" 0.5" 💧 Light watering
Oct 3.5" 2.2" 1.3" 💧 Light watering
Nov 1" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

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

Leeks Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Leeks needs ~1,470 GDD — county provides 1,935 GDD Excellent fit

Leeks Planting Timeline — Hutchinson County, SD

Leeks Planting Calendar

Activity When Date Range
Start Indoors March 27 Mar 27 – Apr 10
Transplant Outdoors May 1 May 1 – May 15
Direct Sow April 17 Apr 17 – May 8
Harvest July 31 Jul 31 – Oct 16
Fall Sowing July 28 Jul 28 – Aug 11

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 Harvest
August Fall Sowing Harvest
September Harvest
October Harvest
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Only during dry spells

📅 Days to Maturity

90–150 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

158 days in Hutchinson County

Growing Tips for Leeks in Hutchinson County

Direct sow Leeks outdoors after May 01 in Hutchinson County when soil has warmed and frost danger has passed.

Your 158.0-day growing season in Hutchinson County is tight for Leeks (90.0-150.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Leeks in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

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 Hutchinson County, SD?

Hutchinson County is in Zone 5a with an average last frost of May 1. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hutchinson County, SD?

Hutchinson County, South Dakota is in USDA Hardiness Zone 5a. The average last spring frost is May 1 and first fall frost is October 6.

🌱

Your Hutchinson County Garden Planner — Free

A 24-page printable planner built for Hutchinson 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 Hutchinson County, SD. Local conditions may vary. Last updated: May 2026.

Sources & credits

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