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When to Plant Tomatoes in Washington County, TN

Tomatoes are the most popular home garden crop, available in thousands of varieties from tiny cherries to massive beefsteaks. They are warm-season plants needing full sun.

Washington County, Tennessee is in USDA Zone 6b. The average last spring frost is April 15 and the first fall frost is October 22, giving you a growing season of approximately 190 days.

At an elevation of 2,969 feet, Washington County receives approximately 41.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Tomatoes during the growing season.

Washington County, TN (Zone 6b) Moderate season
190 days
Last Spring Frost April 15
190 growing days
First Fall Frost October 22

Washington County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (45 days to spare)
Start indoors: Feb 12 Transplant: Apr 23 🍅 Harvest: Jun 25 – Sep 3
Recommended (50%) ✓ Fits season (43 days to spare)
Start indoors: Feb 18 Transplant: Apr 29 🍅 Harvest: Jul 1 – Sep 9
Safe Start (90%) ✓ Fits season (38 days to spare)
Start indoors: Mar 7 Transplant: May 16 🍅 Harvest: Jul 18 – Sep 26

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
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 147 gal / 100 sq ft
Tomatoes needs ~1,214 GDD — county provides 3,182 GDD Excellent fit

Tomatoes Planting Timeline โ€” Washington County, TN

Tomatoes Planting Calendar

Activity When Date Range
Start Indoors February 18 Feb 18 โ€“ Mar 4
Transplant Outdoors April 29 Apr 29 โ€“ May 13
Direct Sow April 22 Apr 22 โ€“ May 13
Harvest July 1 Jul 1 โ€“ Sep 9

Plant 0.5" deep ยท 24" apart ยท Rows 36" 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

60โ€“85 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 6b

Growing Season

190 days

Growing Tips for Washington County

Start seeds indoors 6-8 weeks before last frost. Bury transplants deep to encourage rooting along the stem. Provide consistent moisture to prevent blossom end rot and cracking.

Companion Planting

Good Companions

Avoid Planting Near

  • Cabbage
  • Fennel
  • Potatoes

Level Up Your Garden

๐ŸŒพ Save Your Own Tomatoes Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Scoop seeds from ripe fruit; ferment 2-3 days to remove gel coating.
Storage Store airtight; viable 4-6 years at 35ยฐF, under 45% humidity.

Isolate 25 ft between varieties for purity. Use open-pollinated varieties for true-to-type seeds.

Frequently Asked Questions

When should I plant Tomatoes in Washington County, TN?

Washington County is in Zone 6b with an average last frost of April 15. Plan your Tomatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Washington County, TN?

Washington County, Tennessee is in USDA Hardiness Zone 6b. The average last spring frost is April 15 and first fall frost is October 22.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Washington County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Washington County, TN. Local conditions may vary. Last updated: April 2026.