When to Plant Sunflower in Arizona

Sunflower (Helianthus annuus) is a fast-growing North American native annual famous for its towering stems and brilliant yellow heads. It thrives in full sun and heat, producing large, pollen-rich blooms that attract bees, butterflies, and seed-eating birds. Varieties range from 18-inch dwarfs to 12-foot giants and nearly every color except blue.

Arizona spans USDA hardiness zones 10a, 6b, 7a, 8a, 8b, 9a, 9b (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.

Hover over a county to see details. Click to view planting guide.

Sunflower Planting Calendar for Arizona

▸ Zone 10a ~364 day growing season · Full guide →

Last frost: January 1 · First frost: December 31 · 364 day season

Activity	When	Date Range
Start Indoors	December 11	Dec 11 – Dec 25
Transplant Outdoors	November 20	Nov 20 – Dec 4
Direct Sow	November 20	Nov 20 – Dec 11
Bloom	February 12	Feb 12 – Aug 13

▸ Zone 6b ~205 day growing season · Full guide →

Last frost: April 3 · First frost: October 25 · 205 day season

Activity	When	Date Range
Start Indoors	March 13	Mar 13 – Mar 27
Transplant Outdoors	April 3	Apr 3 – Apr 17
Direct Sow	April 3	Apr 3 – Apr 24
Bloom	June 26	Jun 26 – Sep 25

▸ Zone 7a ~221 day growing season · Full guide →

Last frost: March 25 · First frost: November 1 · 221 day season

Activity	When	Date Range
Start Indoors	March 4	Mar 4 – Mar 18
Transplant Outdoors	March 25	Mar 25 – Apr 8
Direct Sow	March 25	Mar 25 – Apr 15
Bloom	June 17	Jun 17 – Sep 23

▸ Zone 8a ~255 day growing season · Full guide →

Last frost: March 8 · First frost: November 18 · 255 day season

Activity	When	Date Range
Start Indoors	February 15	Feb 15 – Mar 1
Transplant Outdoors	March 1	Mar 1 – Mar 15
Direct Sow	March 1	Mar 1 – Mar 22
Bloom	May 24	May 24 – Sep 27

▸ Zone 8b ~276 day growing season · Full guide →

Last frost: February 25 · First frost: November 28 · 276 day season

Activity	When	Date Range
Start Indoors	February 4	Feb 4 – Feb 18
Transplant Outdoors	February 11	Feb 11 – Feb 25
Direct Sow	February 11	Feb 11 – Mar 4
Bloom	May 6	May 6 – Sep 23

▸ Zone 9a ~303 day growing season · Full guide →

Last frost: February 10 · First frost: December 10 · 303 day season

Activity	When	Date Range
Start Indoors	January 20	Jan 20 – Feb 3
Transplant Outdoors	January 20	Jan 20 – Feb 3
Direct Sow	January 20	Jan 20 – Feb 10
Bloom	April 14	Apr 14 – Sep 15

▸ Zone 9b ~329 day growing season · Full guide →

Last frost: January 25 · First frost: December 20 · 329 day season

Activity	When	Date Range
Start Indoors	January 4	Jan 4 – Jan 18
Transplant Outdoors	December 28	Dec 28 – Jan 11
Direct Sow	December 28	Dec 28 – Jan 18
Bloom	March 22	Mar 22 – Sep 6

Growing Tips for Arizona

Direct-sow 1 inch deep after last frost; germination takes 7-14 days at 65-75°F soil. Sunflowers dislike root disturbance so direct sowing is strongly preferred over transplanting. Plant in succession every 2 weeks for extended bloom. Stake tall varieties. Avoid overwatering — they tolerate drought once established. Birds will self-deadhead seed heads; leave them up through fall for wildlife.

Sunflower in Other States

Frequently Asked Questions

When should I plant Sunflower in Arizona?

Planting dates for Sunflower in Arizona depend on your USDA zone. Arizona spans zones 10a, 6b, 7a, 8a, 8b, 9a, 9b. Check the planting calendar above for your specific zone's frost dates and planting windows.

What zone is Arizona for planting?

Arizona contains USDA hardiness zones 10a, 6b, 7a, 8a, 8b, 9a, 9b. 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.

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