Annual Flower

When to Plant Nasturtiums in North Dakota

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

The Short Answer

In North Dakota, plant nasturtiums based on your regional frost dates. Western North Dakota has a last frost around May 15 - May 30, while Eastern North Dakota sees frost end around May 10 - May 25. Very cold winters. Short but warm summers with long days. Wind protection very important for gardens.

North Dakota Frost Dates

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

Region Zones Last Frost (Spring) First Frost (Fall)
Western North Dakota 3b, 4a May 15 - May 30 Sep 10 - Sep 25
Eastern North Dakota 3a, 3b, 4a, 4b May 10 - May 25 Sep 15 - Sep 30

Nasturtiums Planting Schedule for North Dakota

Western North Dakota (Zones 3b, 4a)

Average last frost: May 15 - May 30 · Average first frost: Sep 10 - Sep 25

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

Eastern North Dakota (Zones 3a, 3b, 4a, 4b)

Average last frost: May 10 - May 25 · Average first frost: Sep 15 - Sep 30

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

Growing Nasturtiums in North Dakota

Nasturtiums in North Dakota's Climate

Nasturtiums add edible beauty to cold-climate gardens from June through frost. Direct sow after last frost — they grow fast in summer warmth. Plant near vegetables as companion and trap plants for aphids. The flowers and leaves have a peppery, watercress-like flavor that brightens salads.

Soil Considerations for North Dakota

Rich prairie soils — excellent for gardening. Alkaline in western regions. Heavy clay in Red River Valley. Make sure soil has warmed to at least 55°F before planting nasturtiums outside.

North Dakota Climate & Growing Season

Very cold winters. Short but warm summers with long days. Wind protection very important for 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 North Dakota: Western North Dakota (3b, 4a) has a last frost around May 15 - May 30, while Eastern North Dakota (3a, 3b, 4a, 4b) sees frost end around May 10 - May 25. 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 North Dakota, but your exact planting dates depend on which region you're in. Western North Dakota gardeners should plan around a May 15 - May 30 last frost, while those in Eastern North Dakota 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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