Annual Flower

When to Plant Nasturtiums in Oklahoma

Edible flowers that double as pest traps. Plant near vegetables to lure aphids away from your food crops.

The Short Answer

In Oklahoma, plant nasturtiums based on your regional frost dates. Northern Oklahoma has a last frost around Apr 5 - Apr 20, while Southern Oklahoma sees frost end around Mar 15 - Apr 1. Hot summers. Severe thunderstorms and tornado risk. Good growing season length. Windy — windbreaks help gardens.

Oklahoma Frost Dates

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

Region Zones Last Frost (Spring) First Frost (Fall)
Northern Oklahoma 6b, 7a Apr 5 - Apr 20 Oct 15 - Nov 1
Central Oklahoma 7a, 7b Mar 25 - Apr 10 Oct 25 - Nov 10
Southern Oklahoma 7b Mar 15 - Apr 1 Nov 1 - Nov 15

Nasturtiums Planting Schedule for Oklahoma

Northern Oklahoma (Zones 6b, 7a)

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

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

Central Oklahoma (Zones 7a, 7b)

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

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

Southern Oklahoma (Zones 7b)

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

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

Growing Nasturtiums in Oklahoma

Nasturtiums in Oklahoma's Climate

Nasturtiums are cool-season flowers in your warm climate. Plant from September through March. They bloom through your mild winter but decline when sustained heat arrives in spring. Their pest-trapping function is particularly valuable during the cooler months when aphid populations are active.

Soil Considerations for Oklahoma

Red clay soils common. Alkaline in west. Rich prairie soils in east. Wind erosion in western panhandle. Make sure soil has warmed to at least 55°F before planting nasturtiums outside.

Oklahoma Climate & Growing Season

Hot summers. Severe thunderstorms and tornado risk. Good growing season length. Windy — windbreaks help gardens. Nasturtiums 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 Oklahoma: Northern Oklahoma (6b, 7a) has a last frost around Apr 5 - Apr 20, while Southern Oklahoma (7b) sees frost end around Mar 15 - Apr 1. This difference matters for nasturtiums — transplant timing shifts by several weeks across the state.

Growing Tips

Both flowers and young leaves are edible with a peppery taste. Thrives in poor soil — too much nitrogen means all leaves, no flowers.

Companion Planting

Plant nasturtiums alongside these companions for better growth:

Tomatoes Cucumbers Squash Beans

The Bottom Line

Nasturtiums can be grown successfully across Oklahoma, but your exact planting dates depend on which region you're in. Northern Oklahoma gardeners should plan around a Apr 5 - Apr 20 last frost, while those in Southern Oklahoma can typically plant earlier. For exact dates based on your zip code, use our free planting date finder.

Related Guides

Nasturtiums Growing Guide National planting guide with all states Oklahoma Planting Calendar All plants for Oklahoma Nasturtiums in Alabama Alabama planting dates Nasturtiums in Alaska Alaska planting dates Nasturtiums in Arizona Arizona planting dates Nasturtiums 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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