Blog

When to Plant Vinca (Annual) in Alaska

Annual vinca (Catharanthus roseus), also called Madagascar periwinkle, is one of the most heat- and drought-tolerant bedding plants available. Glossy foliage stays attractive all season while cheerful pinwheel blooms continue without deadheading. A top performer in hot, humid Southern summers where impatiens and begonias struggle. Self-cleaning; requires little maintenance once established.

Alaska spans USDA hardiness zones 3b, 4a, 4b, 5a, 5b, 6b, 7a, 7b, 8a (with planting data available), so planting dates vary by your location within the state. Click your zone below for the most accurate dates.

Share this guide:

Find Your County

Click your county for exact Vinca (Annual) planting dates based on your local frost dates.

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

Vinca (Annual) Planting Calendar for Alaska

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 February 22 Feb 22 – Mar 8
Transplant Outdoors May 24 May 24 – Jun 7
Bloom August 2 Aug 2 – 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 February 18 Feb 18 – Mar 4
Transplant Outdoors May 20 May 20 – Jun 3
Bloom July 29 Jul 29 – Sep 30
Zone 4b ~155 day growing season · Full guide →

Last frost: May 1 · First frost: October 3 · 155 day season

Activity When Date Range
Start Indoors February 13 Feb 13 – Feb 27
Transplant Outdoors May 15 May 15 – May 29
Bloom July 24 Jul 24 – Oct 2
Zone 5a ~166 day growing season · Full guide →

Last frost: April 25 · First frost: October 8 · 166 day season

Activity When Date Range
Start Indoors February 7 Feb 7 – Feb 21
Transplant Outdoors May 9 May 9 – May 23
Bloom July 18 Jul 18 – Oct 3
Zone 5b ~178 day growing season · Full guide →

Last frost: April 18 · First frost: October 13 · 178 day season

Activity When Date Range
Start Indoors January 31 Jan 31 – Feb 14
Transplant Outdoors April 25 Apr 25 – May 9
Bloom July 4 Jul 4 – Sep 26
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 January 23 Jan 23 – Feb 6
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 14 Jan 14 – Jan 28
Transplant Outdoors March 25 Mar 25 – Apr 8
Bloom June 3 Jun 3 – Sep 23
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 7 Jan 7 – Jan 21
Transplant Outdoors March 18 Mar 18 – Apr 1
Bloom May 27 May 27 – Sep 30
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 December 28 Dec 28 – Jan 11
Transplant Outdoors March 1 Mar 1 – Mar 15
Bloom May 10 May 10 – Sep 27

Growing Tips for Alaska

Start seeds indoors 10–12 weeks before last frost — germination requires warm soil (75–80°F) and darkness. Do not cover seeds deeply; they need just a light dusting. Direct sowing is rarely practiced due to slow seedling establishment. Transplant after soil warms and frost danger has passed. Excellent drought tolerance once established; avoid overwatering. Performs best in well-drained beds or containers in full sun.

Share this guide:

Frequently Asked Questions

When should I plant Vinca (Annual) in Alaska?

Planting dates for Vinca (Annual) in Alaska depend on your USDA zone. Alaska spans zones 3b, 4a, 4b, 5a, 5b, 6b, 7a, 7b, 8a. Check the planting calendar above for your specific zone's frost dates and planting windows.

What zone is Alaska for planting?

Alaska contains USDA hardiness zones 3b, 4a, 4b, 5a, 5b, 6b, 7a, 7b, 8a. 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: June 2026.