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When to Plant Garlic in Charles Mix County, SD

Charles Mix County, South Dakota Zone 5a May

Your May planting checklist for Charles Mix County, South Dakota

A quick May briefing for Charles Mix County, South Dakota gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 3
Avg. first frost October 7
Soil temp (4") 56°F
Watering Low
Pest pressure Low
Daylight 14.5 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.

Charles Mix County, South Dakota is in USDA Zone 5a. The average last spring frost is May 3 and the first fall frost is October 7, giving you a growing season of approximately 157 days.

At an elevation of 667 feet, Charles Mix County receives approximately 27.1 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Garlic to ensure they mature before fall.

Charles Mix County, SD (Zone 5a) Moderate season
157 days
Last Spring Frost May 3
157 growing days
First Fall Frost October 7

Charles Mix County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 28 🍅 Harvest: Jul 28 – Oct 13
Recommended (50%) ✗ May not fit
Transplant: May 3 🍅 Harvest: Aug 2 – Oct 18
Safe Start (90%) ✗ May not fit
Transplant: May 18 🍅 Harvest: Aug 17 – Nov 2

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 Charles Mix County

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

Soil pH

Your soil pH (6.6–7.8) overlaps with Garlic's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.6%). Annual compost additions will help Garlic.

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
0.7″/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 0.7" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 2.8" 0" ❄️ Dormant
May 2.2" 4.3" 0" ✅ Rainfall sufficient
Jun 2.2" 4.4" 0" ✅ Rainfall sufficient
Jul 2.2" 3.9" 0" ✅ Rainfall sufficient
Aug 2.2" 2.9" 0" ✅ Rainfall sufficient
Sep 2.2" 2.4" 0" ✅ Rainfall sufficient
Oct 2.2" 1.8" 0.4" 💧 Light watering
Nov 0.9" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Charles Mix 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 ~2,021 GDD — county provides 1,923 GDD Tight fit

Garlic Planting Timeline — Charles Mix County, SD

Garlic Planting Calendar

Activity When Date Range
Fall Sowing August 26 Aug 26 – Sep 9

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 5a

📆 Growing Season

157 days in Charles Mix County

Growing Tips for Garlic in Charles Mix County

Direct sow Garlic outdoors after May 03 in Charles Mix County when soil has warmed and frost danger has passed.

Your 157.0-day growing season in Charles Mix 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 Charles Mix County, SD?

Charles Mix County is in Zone 5a with an average last frost of May 3. Plan your Garlic planting based on this frost date — see the calendar above for exact timing.

What planting zone is Charles Mix County, SD?

Charles Mix County, South Dakota is in USDA Hardiness Zone 5a. The average last spring frost is May 3 and first fall frost is October 7.

🌱

Your Charles Mix County Garden Planner — Free

A 24-page printable planner built for Charles Mix 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 Charles Mix 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.