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When to plant Garlic in Macoupin County, IL

The best window to plant Garlic in Macoupin County, is mid-spring–late spring, when soil warms to 50°F. Last frost typically hits April 11; first frost October 21. A second sowing from September 9 to September 23 extends the harvest into fall.

When to Plant Garlic in Macoupin County, IL

Garlic

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.

Macoupin County, Illinois is in USDA Zone 6b. The average last spring frost is April 11 and the first fall frost is October 21, giving you a growing season of approximately 193 days.

At an elevation of 859 feet, Macoupin County receives approximately 30.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Garlic during the growing season.

Macoupin County, IL (Zone 6b) Moderate season
193 days
Last Spring Frost April 11
193 growing days
First Fall Frost October 21

Macoupin County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.2

Drainage

Well Drained

Monthly Watering Guide for Garlic

Garlic needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Garlic Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 4.3" 2.7" 1.6" 💧 Light watering
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 3" 1.3" 💧 Light watering
Aug 4.3" 3.6" 0.7" 💧 Light watering
Sep 4.3" 2.7" 1.6" 💧 Light watering
Oct 4.3" 2.1" 2.2" 🚿 Regular watering
Nov 2" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

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

Garlic Planting Timeline — Macoupin County, IL

Garlic Planting Calendar

Activity When Date Range
Harvest December 9 Dec 9 – Mar 24
Fall Sowing September 9 Sep 9 – Sep 23

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

90–240 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 6b

📆 Growing Season

193 days in Macoupin County

Growing Tips for Macoupin County

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 Macoupin County, IL?

Macoupin County is in Zone 6b with an average last frost of April 11. Plan your Garlic planting based on this frost date — see the calendar above for exact timing.

What planting zone is Macoupin County, IL?

Macoupin County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 11 and first fall frost is October 21.

When should I plant Garlic in Macoupin County, IL?

In Macoupin County, IL, plant Garlic after the last frost (around April 11) and before the first frost (around October 21). Best results when soil holds above 50°F.

What growing zone is Macoupin County, IL for Garlic?

Macoupin County sits in USDA Zone 6b. Garlic grows reliably in zones 3a through 9b, so it's a good fit here.

Can Garlic grow in Macoupin County's climate?

Yes — Garlic grows well in Macoupin County's temperate climate. Macoupin County averages a 193-day frost-free season, with last frost around April 11 and first frost around October 21.

🌱

Your Macoupin County Garden Planner — Free

A 22-page printable planner built for Macoupin County (Zone 6b). 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 Macoupin County, IL. Local conditions may vary. Last updated: July 2026.

Sources & credits

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