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When to Plant Potatoes in Johnson County, TN

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

Johnson County, Tennessee is in USDA Zone 6b. The average last spring frost is April 14 and the first fall frost is October 22, giving you a growing season of approximately 191 days.

At an elevation of 404 feet, Johnson County receives approximately 43.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Potatoes during the growing season.

Johnson County, TN (Zone 6b) Moderate season
191 days
Last Spring Frost April 14
191 growing days
First Fall Frost October 22

Johnson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (37 days to spare)
Start indoors: Feb 12 Transplant: Apr 23 🍅 Harvest: Jul 2 – Sep 10
Recommended (50%) ✓ Fits season (37 days to spare)
Start indoors: Feb 17 Transplant: Apr 28 🍅 Harvest: Jul 7 – Sep 15
Safe Start (90%) ✓ Fits season (30 days to spare)
Start indoors: Mar 9 Transplant: May 18 🍅 Harvest: Jul 27 – Oct 5

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
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 102 gal / 100 sq ft
Drought risk

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

Potatoes needs ~1,378 GDD — county provides 2,769 GDD Excellent fit

Potatoes Planting Timeline โ€” Johnson County, TN

Potatoes Planting Calendar

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

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors
April Transplant Outdoors 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 6b

Growing Season

191 days

Growing Tips for Johnson 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 Johnson County, TN?

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

What planting zone is Johnson County, TN?

Johnson County, Tennessee is in USDA Hardiness Zone 6b. The average last spring frost is April 14 and first fall frost is October 22.

๐ŸŒฑ

Plan Your Garden with Confidence

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