When to Plant Petunia in Washington

Petunias (Petunia x hybrida) are warm-season tender annuals prized for their prolific, trumpet-shaped blooms in nearly every color. They perform from hanging baskets to garden borders and bloom continuously from late spring until frost, provided spent flowers are removed regularly.

Washington spans USDA hardiness zones 6a, 6b, 7a, 7b, 8a, 8b, 9a (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 Petunia planting dates based on your local frost dates.

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

Petunia Planting Calendar for Washington

▸ Zone 6a ~193 day growing season · Full guide →

Last frost: April 10 · First frost: October 20 · 193 day season

Activity	When	Date Range
Start Indoors	February 13	Feb 13 – Feb 27
Transplant Outdoors	April 17	Apr 17 – May 1
Bloom	June 26	Jun 26 – Oct 2

▸ 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	February 6	Feb 6 – Feb 20
Transplant Outdoors	April 10	Apr 10 – Apr 24
Bloom	June 19	Jun 19 – Oct 2

▸ 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	January 28	Jan 28 – Feb 11
Transplant Outdoors	April 1	Apr 1 – Apr 15
Bloom	June 10	Jun 10 – Sep 30

▸ Zone 7b ~235 day growing season · Full guide →

Last frost: March 18 · First frost: November 8 · 235 day season

Activity	When	Date Range
Start Indoors	January 21	Jan 21 – Feb 4
Transplant Outdoors	March 18	Mar 18 – Apr 1
Bloom	May 27	May 27 – 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	January 11	Jan 11 – Jan 25
Transplant Outdoors	March 8	Mar 8 – Mar 22
Bloom	May 17	May 17 – Sep 20

▸ 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	December 31	Dec 31 – Jan 14
Transplant Outdoors	February 18	Feb 18 – Mar 4
Bloom	April 29	Apr 29 – Sep 16

▸ 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	December 16	Dec 16 – Dec 30
Transplant Outdoors	January 27	Jan 27 – Feb 10
Bloom	April 7	Apr 7 – Sep 8

Growing Tips for Washington

Start seeds indoors 8–10 weeks before last frost; seeds need light to germinate — press onto moist mix surface, do not cover. Transplant after last frost once nights stay above 50°F. Pinch back leggy plants mid-summer to encourage bushy re-bloom. Wave/spreading types tolerate light shade but bloom less. Feed every 2 weeks with balanced fertilizer once established.

Petunia in Other States

Frequently Asked Questions

When should I plant Petunia in Washington?

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

What zone is Washington for planting?

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

Blog