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When to Plant Garlic in Florence County, WI

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.

Florence County, Wisconsin is in USDA Zone 4a. The average last spring frost is May 26 and the first fall frost is September 21, giving you a growing season of approximately 118 days.

At an elevation of 1,147 feet, Florence County receives approximately 34.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Garlic to ensure they mature before fall.

Florence County, WI (Zone 4a) Short season
118 days
Last Spring Frost May 26
118 growing days
First Fall Frost September 21

Florence County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 20 🍅 Harvest: Aug 19 – Oct 14
Recommended (50%) ✗ May not fit
Transplant: May 26 🍅 Harvest: Aug 25 – Oct 20
Safe Start (90%) ✗ May not fit
Transplant: Jun 11 🍅 Harvest: Sep 10 – Nov 5

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 Florence County

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

Soil pH

Your soil pH (5.8โ€“6.8) overlaps with Garlic's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.4%) โ€” 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
1.2″/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€” 1.2" 0" โ„๏ธ Dormant
Feb โ€” 1.4" 0" โ„๏ธ Dormant
Mar โ€” 2.6" 0" โ„๏ธ Dormant
Apr โ€” 3.4" 0" โ„๏ธ Dormant
May 2.2" 4.4" 0" โœ… Rainfall sufficient
Jun 2.2" 4.4" 0" โœ… Rainfall sufficient
Jul 2.2" 3.2" 0" โœ… Rainfall sufficient
Aug 2.2" 4" 0" โœ… Rainfall sufficient
Sep 2.2" 2.9" 0" โœ… Rainfall sufficient
Oct โ€” 2.7" 0" โ„๏ธ Dormant
Nov โ€” 2.4" 0" โ„๏ธ Dormant
Dec โ€” 1.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Florence 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 ~1,898 GDD — county provides 1,357 GDD May not mature

Garlic Planting Timeline โ€” Florence County, WI

Garlic Planting Calendar

Activity When Date Range
Fall Sowing August 10 Aug 10 โ€“ Aug 24

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 โ€”
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 4a

๐Ÿ“† Growing Season

118 days in Florence County

Growing Tips for Garlic in Florence County

Direct sow Garlic outdoors after May 26 in Florence County when soil has warmed and frost danger has passed.

Your 118.0-day growing season in Florence 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 Florence County, WI?

Florence County is in Zone 4a with an average last frost of May 26. Plan your Garlic planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Florence County, WI?

Florence County, Wisconsin is in USDA Hardiness Zone 4a. The average last spring frost is May 26 and first fall frost is September 21.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Florence County gardeners in Zone 4a 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 Florence County, WI. Local conditions may vary. Last updated: April 2026.