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When to Plant Onion in Hamblen County, TN

Onions are a fundamental kitchen staple available in yellow, white, and red varieties. Choose long-day, short-day, or intermediate types based on your latitude.

Hamblen County, Tennessee is in USDA Zone 7a. 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 3,052 feet, Hamblen County receives approximately 48.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91ยฐF, providing good warmth for Onion during the growing season.

Hamblen County, TN (Zone 7a) Moderate season
190 days
Last Spring Frost April 15
190 growing days
First Fall Frost October 22

Hamblen County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Onion Planting Timeline โ€” Hamblen County, TN

Onion Planting Calendar

Activity When Date Range
Start Indoors March 11 Mar 11 โ€“ Mar 25
Transplant Outdoors April 15 Apr 15 โ€“ Apr 29
Direct Sow April 1 Apr 1 โ€“ Apr 22
Harvest July 15 Jul 15 โ€“ Sep 2
Fall Sowing August 13 Aug 13 โ€“ Aug 27

Plant 1" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

Moderate โ€” regular watering

๐Ÿ“… Days to Maturity

90โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

190 days in Hamblen County

Growing Tips for Hamblen County

Start seeds indoors 8-10 weeks before transplanting. Match day-length type to your latitude. Stop watering when tops begin to fall over and cure bulbs for 2-3 weeks before storage.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans
  • Asparagus

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Onion in Hamblen County, TN?

Hamblen County is in Zone 7a with an average last frost of April 15. Plan your Onion planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Hamblen County, TN?

Hamblen County, Tennessee is in USDA Hardiness Zone 7a. 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 Hamblen County gardeners in Zone 7a 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 Hamblen County, TN. Local conditions may vary. Last updated: April 2026.