Root Vegetable

When to Plant Onions in Tennessee

The backbone of the kitchen garden. Choose short-day, intermediate, or long-day varieties based on your latitude.

The Short Answer

In Tennessee, soil conditions are an important factor for onions. Clay soils over limestone in Middle Tennessee. Rich river bottom soils in west. Rocky mountain soils in east. Direct sow 4 weeks before your last frost date.

Tennessee Frost Dates

Your planting dates depend on which part of Tennessee you're in. Here are the frost date ranges by region:

Region Zones Last Frost (Spring) First Frost (Fall)
East Tennessee 6a, 6b, 7a Apr 5 - Apr 25 Oct 10 - Oct 25
Middle Tennessee 6b, 7a Apr 5 - Apr 20 Oct 15 - Nov 1
West Tennessee 7a, 7b Mar 25 - Apr 10 Oct 20 - Nov 5

Onions Planting Schedule for Tennessee

East Tennessee (Zones 6a, 6b, 7a)

Average last frost: Apr 5 - Apr 25 · Average first frost: Oct 10 - Oct 25

Start Seeds Indoors
10 wks before frost
Transplant Outside
4 wks before frost
Direct Sow
4 wks before frost

Middle Tennessee (Zones 6b, 7a)

Average last frost: Apr 5 - Apr 20 · Average first frost: Oct 15 - Nov 1

Start Seeds Indoors
10 wks before frost
Transplant Outside
4 wks before frost
Direct Sow
4 wks before frost

West Tennessee (Zones 7a, 7b)

Average last frost: Mar 25 - Apr 10 · Average first frost: Oct 20 - Nov 5

Start Seeds Indoors
10 wks before frost
Transplant Outside
4 wks before frost
Direct Sow
4 wks before frost

Growing Onions in Tennessee

Onions in Tennessee's Climate

You straddle the day-length divide. Southern areas need short-day varieties (plant in fall for spring harvest), northern areas can use intermediate-day types. The single most important decision for onion success in your zone is choosing the right day-length type — the wrong one produces scallions instead of bulbs regardless of how well you grow them.

Soil Considerations for Tennessee

Clay soils over limestone in Middle Tennessee. Rich river bottom soils in west. Rocky mountain soils in east. Loose, well-drained soil is especially important for onions since the edible portion grows underground. If your soil is heavy clay, consider raised beds.

Tennessee Climate & Growing Season

Mild four-season climate. Hot, humid summers. Adequate rainfall. Good growing season for wide variety of crops. Onions can handle frost well, which is an advantage in Tennessee's climate. You can push planting dates earlier in spring and extend into fall.

Growing season length varies across Tennessee: East Tennessee (6a, 6b, 7a) has a last frost around Apr 5 - Apr 25, while West Tennessee (7a, 7b) sees frost end around Mar 25 - Apr 10. This difference matters for onions — but onions handle frost well, so the timing difference is less critical.

Growing Tips

Day length triggers bulbing. Northern gardeners need long-day varieties. Southern gardeners need short-day varieties.

Companion Planting

Plant onions alongside these companions for better growth:

Carrots Lettuce Beets Tomatoes

Keep onions away from:

Beans Peas

The Bottom Line

Onions can be grown successfully across Tennessee, but your exact planting dates depend on which region you're in. East Tennessee gardeners should plan around a Apr 5 - Apr 25 last frost, while those in West Tennessee can typically plant earlier. For exact dates based on your zip code, use our free planting date finder.
Note: All dates are based on NOAA 30-year Climate Normals and represent historical averages, not predictions for any specific year. Always check your local weather forecast before planting frost-sensitive crops. Learn about our data sources.

Last reviewed: March 29, 2026

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