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When to Plant Garlic in Hanson County, SD

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.

Hanson County, South Dakota is in USDA Zone 4b. The average last spring frost is May 6 and the first fall frost is October 5, giving you a growing season of approximately 152 days.

At an elevation of 614 feet, Hanson County receives approximately 28.4 inches of rainfall annually with predominantly loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Garlic to ensure they mature before fall.

Hanson County, SD (Zone 4b) Moderate season
152 days
Last Spring Frost May 6
152 growing days
First Fall Frost October 5

Hanson County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (9 days to spare)
Transplant: Apr 27 🍅 Harvest: Jul 27 – Sep 21
Recommended (50%) ✓ Fits season (5 days to spare)
Transplant: May 6 🍅 Harvest: Aug 5 – Sep 30
Safe Start (90%) ✓ Fits season (5 days to spare)
Transplant: May 16 🍅 Harvest: Aug 15 – Oct 10

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 Hanson County

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

Soil pH

Your soil pH (6.4โ€“7.4) is within Garlic's preferred range (6.0โ€“7.5).

Soil Texture

The loam soil in Hanson County is excellent for Garlic โ€” 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
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 โ€” 0.7" 0" โ„๏ธ Dormant
Feb โ€” 0.9" 0" โ„๏ธ Dormant
Mar โ€” 1.7" 0" โ„๏ธ Dormant
Apr โ€” 3.3" 0" โ„๏ธ Dormant
May 2.2" 4.7" 0" โœ… Rainfall sufficient
Jun 2.2" 4.1" 0" โœ… Rainfall sufficient
Jul 2.2" 3.5" 0" โœ… Rainfall sufficient
Aug 2.2" 3.4" 0" โœ… Rainfall sufficient
Sep 2.2" 2.7" 0" โœ… Rainfall sufficient
Oct 2.2" 1.7" 0.5" ๐Ÿ’ง Light watering
Nov โ€” 1.1" 0" โ„๏ธ Dormant
Dec โ€” 0.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Hanson County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 1,862 GDD Tight fit

Garlic Planting Timeline โ€” Hanson County, SD

Garlic Planting Calendar

Activity When Date Range
Fall Sowing August 24 Aug 24 โ€“ Sep 7

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

90โ€“240 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

152 days in Hanson County

Growing Tips for Garlic in Hanson County

Direct sow Garlic outdoors after May 06 in Hanson County when soil has warmed and frost danger has passed.

Your 152.0-day growing season in Hanson 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 Hanson County, SD?

Hanson County is in Zone 4b with an average last frost of May 6. Plan your Garlic planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Hanson County, SD?

Hanson County, South Dakota is in USDA Hardiness Zone 4b. The average last spring frost is May 6 and first fall frost is October 5.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Hanson County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Hanson County, SD. Local conditions may vary. Last updated: April 2026.