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When to Plant Potatoes in Riley County, KS

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

Riley County, Kansas is in USDA Zone 6a. The average last spring frost is April 17 and the first fall frost is October 18, giving you a growing season of approximately 184 days.

At an elevation of 551 feet, Riley County receives approximately 32.9 inches of rainfall annually with predominantly loam soil. Summer highs average 85ยฐF, providing good warmth for Potatoes during the growing season.

Riley County, KS (Zone 6a) Moderate season
184 days
Last Spring Frost April 17
184 growing days
First Fall Frost October 18

Riley County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (28 days to spare)
Start indoors: Feb 16 Transplant: Apr 27 🍅 Harvest: Jul 6 – Sep 14
Recommended (50%) ✓ Fits season (30 days to spare)
Start indoors: Feb 20 Transplant: May 1 🍅 Harvest: Jul 10 – Sep 18
Safe Start (90%) ✓ Fits season (29 days to spare)
Start indoors: Mar 7 Transplant: May 16 🍅 Harvest: Jul 25 – Oct 3

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
0.8″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 1,079 gal / 100 sq ft
Drought risk

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

Potatoes needs ~1,306 GDD — county provides 2,530 GDD Excellent fit

Potatoes Planting Timeline โ€” Riley County, KS

Potatoes Planting Calendar

Activity When Date Range
Start Indoors February 20 Feb 20 โ€“ Mar 6
Transplant Outdoors May 1 May 1 โ€“ May 15
Direct Sow April 24 Apr 24 โ€“ May 15
Harvest July 10 Jul 10 โ€“ Sep 18

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors
April Direct Sow
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 6a

Growing Season

184 days

Growing Tips for Riley 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 Riley County, KS?

Riley County is in Zone 6a with an average last frost of April 17. Plan your Potatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Riley County, KS?

Riley County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 17 and first fall frost is October 18.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Riley County gardeners in Zone 6a 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 Riley County, KS. Local conditions may vary. Last updated: April 2026.