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When to Plant Tomatillo in Knox County, TN

Tomatillos are a Mexican staple that produces tart, green fruits enclosed in papery husks. They are essential for salsa verde and green sauces.

Knox County, Tennessee is in USDA Zone 7a. The average last spring frost is April 10 and the first fall frost is October 29, giving you a growing season of approximately 202 days.

At an elevation of 2,448 feet, Knox County receives approximately 47.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 93ยฐF, providing good warmth for Tomatillo during the growing season.

Knox County, TN (Zone 7a) Long season
202 days
Last Spring Frost April 10
202 growing days
First Fall Frost October 29

Knox County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (53 days to spare)
Start indoors: Feb 14 Transplant: Apr 18 🍅 Harvest: Jun 20 – Aug 29
Recommended (50%) ✓ Fits season (55 days to spare)
Start indoors: Feb 20 Transplant: Apr 24 🍅 Harvest: Jun 26 – Sep 4
Safe Start (90%) ✓ Fits season (51 days to spare)
Start indoors: Mar 7 Transplant: May 9 🍅 Harvest: Jul 11 – Sep 19

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
0.0″/week
Watering frequency Only during dry spells
Season total 18 gal / 100 sq ft
Drought risk

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

Tomatillo needs ~1,432 GDD — county provides 3,989 GDD Excellent fit

Tomatillo Planting Timeline โ€” Knox County, TN

Tomatillo Planting Calendar

Activity When Date Range
Start Indoors February 20 Feb 20 โ€“ Mar 6
Transplant Outdoors April 24 Apr 24 โ€“ May 8
Direct Sow April 17 Apr 17 โ€“ May 8
Harvest June 26 Jun 26 โ€“ Sep 4

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 Harvest
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 7a

Growing Season

202 days

Growing Tips for Knox County

Start seeds indoors 6-8 weeks before last frost. Plant at least two plants for cross-pollination. Harvest when fruits fill the husk and it begins to split.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel
  • Dill

Level Up Your Garden

Frequently Asked Questions

When should I plant Tomatillo in Knox County, TN?

Knox County is in Zone 7a with an average last frost of April 10. Plan your Tomatillo planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Knox County, TN?

Knox County, Tennessee is in USDA Hardiness Zone 7a. The average last spring frost is April 10 and first fall frost is October 29.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Knox County gardeners in Zone 7a 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 Knox County, TN. Local conditions may vary. Last updated: April 2026.