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When to Plant Garlic in Buffalo 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.

Buffalo County, South Dakota is in USDA Zone 4b. The average last spring frost is May 9 and the first fall frost is October 5, giving you a growing season of approximately 149 days.

At an elevation of 840 feet, Buffalo County receives approximately 23.7 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.

Buffalo County, SD (Zone 4b) Short season
149 days
Last Spring Frost May 9
149 growing days
First Fall Frost October 5

Buffalo 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 (5 days to spare)
Transplant: May 1 🍅 Harvest: Jul 31 – Sep 25
Recommended (50%) ✓ Fits season (2 days to spare)
Transplant: May 9 🍅 Harvest: Aug 8 – Oct 3
Safe Start (90%) ✓ Fits season (1 days to spare)
Transplant: May 20 🍅 Harvest: Aug 19 – Oct 14

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 Buffalo County

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

Soil pH

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

Soil Texture

The loam soil in Buffalo County is excellent for Garlic โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Garlic.

Organic Matter

Organic matter is moderate (3.5%). 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

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€” 0.6" 0" โ„๏ธ Dormant
Feb โ€” 0.9" 0" โ„๏ธ Dormant
Mar โ€” 1.5" 0" โ„๏ธ Dormant
Apr โ€” 2.2" 0" โ„๏ธ Dormant
May 2.2" 3.2" 0" โœ… Rainfall sufficient
Jun 2.2" 4.3" 0" โœ… Rainfall sufficient
Jul 2.2" 3.4" 0" โœ… Rainfall sufficient
Aug 2.2" 2.6" 0" โœ… Rainfall sufficient
Sep 2.2" 2.1" 0.1" ๐Ÿ’ง Light watering
Oct 2.2" 1.6" 0.6" ๐Ÿ’ง Light watering
Nov โ€” 0.8" 0" โ„๏ธ Dormant
Dec โ€” 0.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Buffalo 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 1,825 GDD Tight fit

Garlic Planting Timeline โ€” Buffalo 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: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

149 days in Buffalo County

Growing Tips for Garlic in Buffalo County

Direct sow Garlic outdoors after May 09 in Buffalo County when soil has warmed and frost danger has passed.

Your 149.0-day growing season in Buffalo 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 Buffalo County, SD?

Buffalo County is in Zone 4b with an average last frost of May 9. Plan your Garlic planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Buffalo County, SD?

Buffalo County, South Dakota is in USDA Hardiness Zone 4b. The average last spring frost is May 9 and first fall frost is October 5.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Buffalo 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 Buffalo County, SD. Local conditions may vary. Last updated: April 2026.