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When to Plant Potatoes in Hamilton County, TN

Hamilton County, Tennessee Zone 8a May

Your May gardening checklist

Each item below is timed to Hamilton County, Tennessee's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost March 28
Avg. first frost November 1
Soil temp (4") 59°F
Watering Low
Pest pressure Moderate
Daylight 13.8 hrs
  1. Start potatoes indoors

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

Get ahead of June
  • First harvests: potatoes

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

Hamilton County, Tennessee is in USDA Zone 8a. The average last spring frost is March 28 and the first fall frost is November 1, giving you a growing season of approximately 218 days.

At an elevation of 3,918 feet, Hamilton County receives approximately 51.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 93°F, providing good warmth for Potatoes during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Potatoes root diseases.

Hamilton County, TN (Zone 8a) Long season
218 days
Last Spring Frost March 28
218 growing days
First Fall Frost November 1

Hamilton County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (67 days to spare)
Start indoors: Jan 31 Transplant: Apr 4 🍅 Harvest: Jun 13 – Aug 22
Recommended (50%) ✓ Fits season (64 days to spare)
Start indoors: Feb 7 Transplant: Apr 11 🍅 Harvest: Jun 20 – Aug 29
Safe Start (90%) ✓ Fits season (64 days to spare)
Start indoors: Feb 27 Transplant: May 1 🍅 Harvest: Jul 10 – Sep 18

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.

Soil Compatibility in Hamilton County

How your county's soil matches Potatoes's growing requirements.

Soil pH

Your soil pH (5.6–6.9) overlaps with Potatoes's range (5.0–6.5), though not a perfect match.

Soil Texture

The silt loam soil in Hamilton County is excellent for Potatoes — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Potatoes.

How to Plant Potatoes

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Succession Planting Potatoes

3
successive plantings in your 218-day season

Sow every 8 weeks. Last sowing by Jul 04 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 19 gal / 100 sq ft

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 4.3" 0" ❄️ Dormant
Feb 4.5" 0" ❄️ Dormant
Mar 4.3" 4.8" 0" ✅ Rainfall sufficient
Apr 4.3" 4" 0.3" 💧 Light watering
May 4.3" 4.3" 0" ✅ Rainfall sufficient
Jun 4.3" 4.6" 0" ✅ Rainfall sufficient
Jul 4.3" 5.4" 0" ✅ Rainfall sufficient
Aug 4.3" 5.2" 0" ✅ Rainfall sufficient
Sep 4.3" 3.8" 0.5" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 4.3" 4.2" 0.1" 💧 Light watering
Dec 3.6" 0" ❄️ Dormant

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

Potatoes Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Potatoes needs ~1,876 GDD — county provides 4,305 GDD Excellent fit

Potatoes Planting Timeline — Hamilton County, TN

Potatoes Planting Calendar

Activity When Date Range
Start Indoors February 7 Feb 7 – Feb 21
Transplant Outdoors April 11 Apr 11 – Apr 25
Direct Sow April 4 Apr 4 – Apr 25
Harvest June 20 Jun 20 – Aug 29

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

70–120 days

🧪 Soil pH

Needs 5–6.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

218 days in Hamilton County

Growing Tips for Potatoes in Hamilton County

Direct sow Potatoes outdoors after March 28 in Hamilton County when soil has warmed and frost danger has passed.

Common pests for Potatoes in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

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 Hamilton County, TN?

Hamilton County is in Zone 8a with an average last frost of March 28. Plan your Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hamilton County, TN?

Hamilton County, Tennessee is in USDA Hardiness Zone 8a. The average last spring frost is March 28 and first fall frost is November 1.

🌱

Your Hamilton County Garden Planner — Free

A 24-page printable planner built for Hamilton County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Hamilton County, TN. Local conditions may vary. Last updated: May 2026.

Sources & credits

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