Blog

When to Plant Sunflower in Northwest Territories

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.

Northwest Territories spans USDA hardiness zones 2b, 3a (with planting data available), so planting dates vary by your location within the state. Click your zone below for the most accurate dates.

Find Your County

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

Sunflower Planting Calendar for Northwest Territories

Zone 2b ~111 day growing season · Full guide →

Last frost: May 22 · First frost: September 10 · 111 day season

Activity When Date Range
Start Indoors March 20 Mar 20 – Apr 3
Transplant Outdoors June 12 Jun 12 – Jun 26
Direct Sow June 5 Jun 5 – Jun 26
Harvest August 21 Aug 21 – Oct 9
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

Growing Tips for Northwest Territories

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 Northwest Territories?

Planting dates for Sunflower in Northwest Territories depend on your USDA zone. Northwest Territories spans zones 2b, 3a. Check the planting calendar above for your specific zone's frost dates and planting windows.

What zone is Northwest Territories for planting?

Northwest Territories contains USDA hardiness zones 2b, 3a. 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.