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When to Plant Garlic in Deuel County, SD

Deuel County, South Dakota Zone 4b May

Deuel County, South Dakota gardeners: here's your May plan

Each item below is timed to Deuel County, South Dakota's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 2
Avg. first frost October 1
Soil temp (4") 56°F
Watering Low
Pest pressure Low
Daylight 14.6 hrs

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Garlic is a pungent allium planted in fall and harvested the following summer. Hardneck varieties produce edible flower stalks (scapes) and are more cold-hardy.

Deuel County, South Dakota is in USDA Zone 4b. The average last spring frost is May 2 and the first fall frost is October 1, giving you a growing season of approximately 152 days.

At an elevation of 693 feet, Deuel County receives approximately 32.5 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Garlic to ensure they mature before fall.

Deuel County, SD (Zone 4b) Moderate season
152 days
Last Spring Frost May 2
152 growing days
First Fall Frost October 1

Deuel County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (2 days to spare)
Transplant: Apr 27 🍅 Harvest: Jul 27 – Sep 21
Recommended (50%) ✓ Fits season (5 days to spare)
Transplant: May 2 🍅 Harvest: Aug 1 – Sep 26
Safe Start (90%) ✓ Fits season (4 days to spare)
Transplant: May 15 🍅 Harvest: Aug 14 – Oct 9

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 Deuel County

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

Soil pH

Your soil pH (6.5–7.8) overlaps with Garlic's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — Garlic will thrive.

How to Plant Garlic

1"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 6 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Garlic

Garlic needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Garlic Needs Rainfall You Supplement Action
Jan 0.8" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 3.4" 0" ❄️ Dormant
May 2.2" 5.2" 0" ✅ Rainfall sufficient
Jun 2.2" 5" 0" ✅ Rainfall sufficient
Jul 2.2" 4.3" 0" ✅ Rainfall sufficient
Aug 2.2" 3.5" 0" ✅ Rainfall sufficient
Sep 2.2" 3.4" 0" ✅ Rainfall sufficient
Oct 2.2" 2" 0.2" 💧 Light watering
Nov 1.2" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

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

Garlic 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.

Garlic needs ~1,898 GDD — county provides 1,748 GDD Tight fit

Garlic Planting Timeline — Deuel County, SD

Garlic Planting Calendar

Activity When Date Range
Fall Sowing August 20 Aug 20 – Sep 3

Plant 1" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June
July
August Fall Sowing
September Fall Sowing
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

90–240 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

152 days in Deuel County

Growing Tips for Garlic in Deuel County

Direct sow Garlic outdoors after May 02 in Deuel County when soil has warmed and frost danger has passed.

Your 152.0-day growing season in Deuel County is tight for Garlic (90.0-240.0 days to maturity). Start indoors and choose early-maturing varieties.

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

General growing tips

Plant individual cloves pointed end up in fall, 6 weeks before ground freezes. Mulch heavily with straw. Harvest when lower leaves begin to brown but 5-6 green leaves remain.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans
  • Asparagus

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Garlic in Deuel County, SD?

Deuel County is in Zone 4b with an average last frost of May 2. Plan your Garlic planting based on this frost date — see the calendar above for exact timing.

What planting zone is Deuel County, SD?

Deuel County, South Dakota is in USDA Hardiness Zone 4b. The average last spring frost is May 2 and first fall frost is October 1.

🌱

Your Deuel County Garden Planner — Free

A 24-page printable planner built for Deuel 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.

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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 Deuel 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.