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When to Plant Onion in Dickson 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.

Dickson County, Tennessee is in USDA Zone 7a. The average last spring frost is April 4 and the first fall frost is October 29, giving you a growing season of approximately 208 days.

At an elevation of 2,147 feet, Dickson County receives approximately 54 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92ยฐF, providing good warmth for Onion during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Onion root diseases.

Dickson County, TN (Zone 7a) Long season
208 days
Last Spring Frost April 4
208 growing days
First Fall Frost October 29

Dickson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (70 days to spare)
Start indoors: Feb 21 Transplant: Mar 28 🍅 Harvest: Jun 27 – Aug 15
Recommended (50%) ✓ Fits season (68 days to spare)
Start indoors: Feb 28 Transplant: Apr 4 🍅 Harvest: Jul 4 – Aug 22
Safe Start (90%) ✓ Fits season (70 days to spare)
Start indoors: Mar 14 Transplant: Apr 18 🍅 Harvest: Jul 18 – Sep 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
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Onion needs ~1,995 GDD — county provides 3,952 GDD Excellent fit

Onion Planting Timeline โ€” Dickson County, TN

Onion Planting Calendar

Activity When Date Range
Start Indoors February 28 Feb 28 โ€“ Mar 14
Transplant Outdoors April 4 Apr 4 โ€“ Apr 18
Direct Sow March 21 Mar 21 โ€“ Apr 11
Fall Sowing August 20 Aug 20 โ€“ Sep 3
Harvest July 4 Jul 4 โ€“ Aug 22

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

90โ€“120 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 7a

Growing Season

208 days

Growing Tips for Dickson 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

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Frequently Asked Questions

When should I plant Onion in Dickson County, TN?

Dickson County is in Zone 7a with an average last frost of April 4. Plan your Onion planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Dickson County, TN?

Dickson County, Tennessee is in USDA Hardiness Zone 7a. The average last spring frost is April 4 and first fall frost is October 29.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Dickson 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 Dickson County, TN. Local conditions may vary. Last updated: April 2026.