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When to plant Potatoes in Randolph County County,

Randolph County County's climate puts the Potatoes spring window between April 18 and May 9. most warm-season crops establish quickly once soil holds above 60°F.

When to Plant Potatoes in Randolph 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.

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 Potatoes 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

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 Randolph County's 192-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 1.2" 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.

Potatoes Planting Timeline — Randolph County, IL

Potatoes Planting Calendar

Activity When Date Range
Start Indoors February 21 Feb 21 – Mar 7
Transplant Outdoors April 25 Apr 25 – May 9
Direct Sow April 18 Apr 18 – May 9
Harvest July 4 Jul 4 – Sep 12

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 7a

📆 Growing Season

192 days in Randolph County

Growing Tips for Randolph 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 Randolph County, IL?

Randolph County is in Zone 7a with an average last frost of April 11. Plan your Potatoes 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 Potatoes in Randolph County County, ?

In Randolph County County, , plant Potatoes 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 County, for Potatoes?

Randolph County County sits in USDA Zone 7a. Potatoes grows reliably in zones 3a through 10b, so it's a good fit here.

Can Potatoes grow in Randolph County County's climate?

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

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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.

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 Randolph 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.