Annual Flower

When to Plant Cosmos in Tennessee

Delicate, daisy-like blooms that dance in the breeze. Cosmos thrive in poor soil and practically grow themselves.

The Short Answer

In Tennessee, plant cosmos based on your regional frost dates. East Tennessee has a last frost around Apr 5 - Apr 25, while West Tennessee sees frost end around Mar 25 - Apr 10. Mild four-season climate. Hot, humid summers. Adequate rainfall. Good growing season for wide variety of crops.

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

Cosmos 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
4 wks before frost
Transplant Outside
1 wks after frost
Direct Sow
1 wks after frost

Middle Tennessee (Zones 6b, 7a)

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

Start Seeds Indoors
4 wks before frost
Transplant Outside
1 wks after frost
Direct Sow
1 wks after frost

West Tennessee (Zones 7a, 7b)

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

Start Seeds Indoors
4 wks before frost
Transplant Outside
1 wks after frost
Direct Sow
1 wks after frost

Growing Cosmos in Tennessee

Cosmos in Tennessee's Climate

Cosmos love your heat and sun. Plant from March and enjoy blooms for 6+ months. They handle drought well — one of the most water-efficient flowers for warm-climate gardens. Let some flowers go to seed for naturalized volunteer displays in subsequent years.

Soil Considerations for Tennessee

Clay soils over limestone in Middle Tennessee. Rich river bottom soils in west. Rocky mountain soils in east. Make sure soil has warmed to at least 60°F before planting cosmos outside.

Tennessee Climate & Growing Season

Mild four-season climate. Hot, humid summers. Adequate rainfall. Good growing season for wide variety of crops. Cosmos cannot tolerate any frost, so wait until all frost danger has passed before transplanting outside. Watch local forecasts carefully in spring.

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 cosmos — transplant timing shifts by several weeks across the state.

Growing Tips

Don't over-fertilize — rich soil produces more leaves and fewer flowers. Let some flowers go to seed for next year's crop.

Companion Planting

Plant cosmos alongside these companions for better growth:

Tomatoes Squash

The Bottom Line

Cosmos 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.

Related Guides

Cosmos Growing Guide National planting guide with all states Tennessee Planting Calendar All plants for Tennessee Cosmos in Alabama Alabama planting dates Cosmos in Alaska Alaska planting dates Cosmos in Arizona Arizona planting dates Cosmos in Arkansas Arkansas planting dates
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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