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When to plant Garlic in Randolph County, IL

Randolph County's climate puts the Garlic spring window between mid-spring and late spring. most warm-season crops establish quickly once soil holds above 60°F. A second sowing from September 8 to September 22 extends the harvest into fall.

When to Plant Garlic in Randolph 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.

Randolph County, Illinois is in USDA Zone 7a. The average last spring frost is April 11 and the first fall frost is October 20, giving you a growing season of approximately 192 days.

At an elevation of 501 feet, Randolph County receives approximately 32.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Garlic during the growing season.

Randolph County, IL (Zone 7a) Moderate season
192 days
Last Spring Frost April 11
192 growing days
First Fall Frost October 20

Randolph County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.8

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 1.2" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 3.6" 0.7" 💧 Light watering
Aug 4.3" 3" 1.3" 💧 Light watering
Sep 4.3" 3.2" 1.1" 💧 Light watering
Oct 4.3" 2.4" 1.9" 💧 Light watering
Nov 2.2" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

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

Garlic Planting Timeline — Randolph County, IL

Garlic Planting Calendar

Activity When Date Range
Harvest December 8 Dec 8 – Apr 20
Fall Sowing September 8 Sep 8 – Sep 22

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

Month-by-Month Timeline

MonthActivities
January Harvest
February Harvest
March Harvest
April Harvest
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 7a

📆 Growing Season

192 days in Randolph County

Growing Tips for Randolph 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 Randolph County, IL?

Randolph County is in Zone 7a 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 Randolph County, IL?

Randolph County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 11 and first fall frost is October 20.

When should I plant Garlic in Randolph County, IL?

In Randolph County, IL, plant Garlic after the last frost (around April 11) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Randolph County, IL for Garlic?

Randolph County sits in USDA Zone 7a. Garlic grows reliably in zones 3a through 9b, so it's a good fit here.

Can Garlic grow in Randolph County's climate?

Yes — Garlic grows well in Randolph County's temperate climate. Randolph County averages a 192-day frost-free season, with last frost around April 11 and first frost around October 20.

🌱

Your Randolph County Garden Planner — Free

A 22-page printable planner built for Randolph County (Zone 7a). 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 Randolph County, IL. Local conditions may vary. Last updated: July 2026.

Sources & credits

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