Annual Flower

When to Plant Cosmos in Mississippi

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

The Short Answer

In Mississippi, plant cosmos based on your regional frost dates. Northern Mississippi has a last frost around Mar 15 - Apr 1, while Southern Mississippi sees frost end around Feb 15 - Mar 5. Long growing season. Hot, humid summers. Mild winters. Two-season gardening possible.

Mississippi Frost Dates

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

Region Zones Last Frost (Spring) First Frost (Fall)
Northern Mississippi 7b, 8a Mar 15 - Apr 1 Nov 1 - Nov 15
Central Mississippi 8a, 8b Mar 1 - Mar 15 Nov 10 - Nov 25
Southern Mississippi 8b, 9a Feb 15 - Mar 5 Nov 15 - Dec 5

Cosmos Planting Schedule for Mississippi

Northern Mississippi (Zones 7b, 8a)

Average last frost: Mar 15 - Apr 1 · Average first frost: Nov 1 - Nov 15

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

Central Mississippi (Zones 8a, 8b)

Average last frost: Mar 1 - Mar 15 · Average first frost: Nov 10 - Nov 25

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

Southern Mississippi (Zones 8b, 9a)

Average last frost: Feb 15 - Mar 5 · Average first frost: Nov 15 - Dec 5

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

Growing Cosmos in Mississippi

Cosmos in Mississippi'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 Mississippi

Rich delta soils in west. Heavy clay in many areas. Sandy in pine belt. Acidic throughout. Make sure soil has warmed to at least 60°F before planting cosmos outside.

Mississippi Climate & Growing Season

Long growing season. Hot, humid summers. Mild winters. Two-season gardening possible. 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 Mississippi: Northern Mississippi (7b, 8a) has a last frost around Mar 15 - Apr 1, while Southern Mississippi (8b, 9a) sees frost end around Feb 15 - Mar 5. 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 Mississippi, but your exact planting dates depend on which region you're in. Northern Mississippi gardeners should plan around a Mar 15 - Apr 1 last frost, while those in Southern Mississippi 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 Mississippi Planting Calendar All plants for Mississippi 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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