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When to Plant Potatoes in Carroll County, IA

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

Carroll County, Iowa is in USDA Zone 5a. The average last spring frost is April 27 and the first fall frost is October 5, giving you a growing season of approximately 161 days.

At an elevation of 751 feet, Carroll County receives approximately 38.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Potatoes during the growing season.

Carroll County, IA (Zone 5a) Moderate season
161 days
Last Spring Frost April 27
161 growing days
First Fall Frost October 5

Carroll County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (5 days to spare)
Start indoors: Feb 25 Transplant: May 6 🍅 Harvest: Jul 15 – Sep 23
Recommended (50%) ✓ Fits season (7 days to spare)
Start indoors: Mar 2 Transplant: May 11 🍅 Harvest: Jul 20 – Sep 28
Safe Start (90%) ✓ Fits season (5 days to spare)
Start indoors: Mar 16 Transplant: May 25 🍅 Harvest: Aug 3 – Oct 12

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Potatoes needs ~1,449 GDD — county provides 2,455 GDD Excellent fit

Potatoes Planting Timeline โ€” Carroll County, IA

Potatoes Planting Calendar

Activity When Date Range
Start Indoors March 2 Mar 2 โ€“ Mar 16
Transplant Outdoors May 11 May 11 โ€“ May 25
Direct Sow May 4 May 4 โ€“ May 25
Harvest July 20 Jul 20 โ€“ Sep 28

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

70โ€“120 days

Soil pH

5 โ€“ 6.5

USDA Zone

Zone 5a

Growing Season

161 days

Growing Tips for Carroll 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Potatoes in Carroll County, IA?

Carroll County is in Zone 5a with an average last frost of April 27. Plan your Potatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Carroll County, IA?

Carroll County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 27 and first fall frost is October 5.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Carroll County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

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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 Carroll County, IA. Local conditions may vary. Last updated: April 2026.