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When to plant Potatoes in Clinton County, IL

For Potatoes in Clinton County, the safe spring window opens around April 17 and closes around May 8. Last expected frost is April 10, first fall frost October 19, giving a 192-day growing season.

When to Plant Potatoes in Clinton County, IL

Potatoes

Potatoes are a versatile staple crop that produces tubers underground. They come in hundreds of varieties with varying colors, textures, and maturity dates.

Clinton County, Illinois is in USDA Zone 6b. The average last spring frost is April 10 and the first fall frost is October 19, giving you a growing season of approximately 192 days.

At an elevation of 1,142 feet, Clinton County receives approximately 38.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Potatoes during the growing season.

Clinton County, IL (Zone 6b) Moderate season
192 days
Last Spring Frost April 10
192 growing days
First Fall Frost October 19

Clinton County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

How Much Potatoes to Grow

3-5 lbs
Average yield per plant
5
Plants per person
10 sq ft
Space per person

For a family of 4, plant approximately 20 potatoes plants in about 40 sq ft. In Clinton County's 192-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Potatoes Planting Timeline — Clinton County, IL

Potatoes Planting Calendar

Activity When Date Range
Start Indoors February 13 Feb 13 – Feb 27
Transplant Outdoors April 24 Apr 24 – May 8
Direct Sow April 17 Apr 17 – May 8
Harvest July 3 Jul 3 – Sep 11

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June
July Harvest
August Harvest
September Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

70–120 days

🧪 Soil pH

Needs 5–6.5 · Your soil: N/A

🗺️ USDA Zone

Zone 6b

📆 Growing Season

192 days in Clinton County

Growing Tips for Clinton County

Plant seed potatoes (not grocery store potatoes) 4 inches deep in spring. Hill soil around stems as plants grow to prevent greening. Stop watering when plants die back.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Cucumber
  • Squash Summer

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Potatoes in Clinton County, IL?

Clinton County is in Zone 6b with an average last frost of April 10. Plan your Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clinton County, IL?

Clinton County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 10 and first fall frost is October 19.

When should I plant Potatoes in Clinton County, IL?

In Clinton County, IL, plant Potatoes after the last frost (around April 10) and before the first frost (around October 19). Best results when soil holds above 50°F.

What growing zone is Clinton County, IL for Potatoes?

Clinton County sits in USDA Zone 6b. Potatoes grows reliably in zones 3a through 10b, so it's a good fit here.

Can Potatoes grow in Clinton County's climate?

Yes — Potatoes grows well in Clinton County's temperate climate. Clinton County averages a 192-day frost-free season, with last frost around April 10 and first frost around October 19.

🌱

Your Clinton County Garden Planner — Free

A 22-page printable planner built for Clinton 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.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.