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When to Plant Sunflower in North Dakota

Sunflowers are tall, cheerful annuals grown for their edible seeds and as pollinator magnets. They come in sizes from 2-foot dwarfs to 12-foot giants.

North Dakota spans USDA hardiness zones 3a, 3b, 4a (with planting data available), so planting dates vary by your location within the state. Click your zone below for the most accurate dates.

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Click your county for exact Sunflower planting dates based on your local frost dates.

Sunflower Planting Calendar for North Dakota

Zone 3a ~123 day growing season · Full guide →

Last frost: May 15 · First frost: September 15 · 123 day season

Activity When Date Range
Start Indoors March 13 Mar 13 – Mar 27
Transplant Outdoors June 5 Jun 5 – Jun 19
Direct Sow May 29 May 29 – Jun 19
Harvest August 14 Aug 14 – Oct 2
Zone 3b ~135 day growing season · Full guide →

Last frost: May 10 · First frost: September 22 · 135 day season

Activity When Date Range
Start Indoors March 8 Mar 8 – Mar 22
Transplant Outdoors May 31 May 31 – Jun 14
Direct Sow May 24 May 24 – Jun 14
Harvest August 9 Aug 9 – Sep 27
Zone 4a ~145 day growing season · Full guide →

Last frost: May 6 · First frost: September 28 · 145 day season

Activity When Date Range
Start Indoors March 4 Mar 4 – Mar 18
Transplant Outdoors May 27 May 27 – Jun 10
Direct Sow May 20 May 20 – Jun 10
Harvest August 5 Aug 5 – Sep 23

Growing Tips for North Dakota

Direct sow after last frost. Stake tall varieties in windy areas. Harvest seed heads when the back turns brown and seeds are plump. Dry heads upside down.

Frequently Asked Questions

When should I plant Sunflower in North Dakota?

Planting dates for Sunflower in North Dakota depend on your USDA zone. North Dakota spans zones 3a, 3b, 4a. Check the planting calendar above for your specific zone's frost dates and planting windows.

What zone is North Dakota for planting?

North Dakota contains USDA hardiness zones 3a, 3b, 4a. Your specific zone depends on your location within the state — northern and higher-elevation areas are in colder zones, while southern and coastal areas are warmer.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Last updated: April 2026.