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When to plant Potatoes in Clay County County,

In Clay County County, plant Potatoes in spring between April 21 and May 12, once soil temps hold above 50°F. Clay County County's last frost averages April 14, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between and — roughly 120 days before the first frost on October 17.

When to Plant Potatoes in Clay 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.

Clay County, Illinois is in USDA Zone 6b. The average last spring frost is April 14 and the first fall frost is October 17, giving you a growing season of approximately 186 days.

At an elevation of 1,105 feet, Clay County receives approximately 34.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Potatoes during the growing season.

Clay County, IL (Zone 6b) Moderate season
186 days
Last Spring Frost April 14
186 growing days
First Fall Frost October 17

Clay County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.9

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 Clay County's 186-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Monthly Watering Guide for Potatoes

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

Month Potatoes Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 4.3" 3.8" 0.5" 💧 Light watering
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 4.1" 0.2" 💧 Light watering
Jul 4.3" 3.7" 0.6" 💧 Light watering
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 2.8" 1.5" 💧 Light watering
Oct 4.3" 2.6" 1.7" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

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

Potatoes Planting Timeline — Clay County, IL

Potatoes Planting Calendar

Activity When Date Range
Start Indoors February 17 Feb 17 – Mar 3
Transplant Outdoors April 28 Apr 28 – May 12
Direct Sow April 21 Apr 21 – May 12
Harvest July 7 Jul 7 – Sep 15

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
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

186 days in Clay County

Growing Tips for Clay 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 Clay County, IL?

Clay County is in Zone 6b with an average last frost of April 14. Plan your Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clay County, IL?

Clay County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 14 and first fall frost is October 17.

When should I plant Potatoes in Clay County County, ?

In Clay County County, , plant Potatoes after the last frost (around April 14) and before the first frost (around October 17). Best results when soil holds above 50°F.

What growing zone is Clay County County, for Potatoes?

Clay County 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 Clay County County's climate?

Yes — Potatoes grows well in Clay County County's temperate climate. Clay County County averages a 186-day frost-free season, with last frost around April 14 and first frost around October 17.

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Your Clay County Garden Planner — Free

A 22-page printable planner built for Clay 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 Clay County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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