Blog

When to Plant Bachelor's Button in Oklahoma

Bachelor's Button (Centaurea cyanus), also called cornflower, is a carefree cool-season annual best known for its vivid cobalt-blue flowers — one of the truest blues in the annual garden. It tolerates light frosts, self-seeds prolifically, and thrives in poor to average soils. A traditional cut flower and pollinator magnet, it has been cultivated in gardens for centuries.

Oklahoma spans USDA hardiness zones 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 Bachelor's Button planting dates based on your local frost dates.

Bachelor's Button Planting Calendar for Oklahoma

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 20 Feb 20 – Mar 6
Transplant Outdoors April 3 Apr 3 – Apr 17
Direct Sow March 6 Mar 6 – Mar 27
Bloom June 5 Jun 5 – Aug 28
Fall Sowing September 13 Sep 13 – Sep 27
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 February 11 Feb 11 – Feb 25
Transplant Outdoors March 25 Mar 25 – Apr 8
Direct Sow February 18 Feb 18 – Mar 11
Bloom May 27 May 27 – Aug 26
Fall Sowing September 6 Sep 6 – Sep 20
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 February 4 Feb 4 – Feb 18
Transplant Outdoors March 18 Mar 18 – Apr 1
Direct Sow February 11 Feb 11 – Mar 4
Bloom May 20 May 20 – Aug 26
Fall Sowing September 13 Sep 13 – Sep 27
Zone 8a ~255 day growing season · Full guide →

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

Activity When Date Range
Transplant Outdoors February 22 Feb 22 – Mar 8
Direct Sow January 25 Jan 25 – Feb 15
Bloom April 26 Apr 26 – Aug 9
Fall Sowing September 23 Sep 23 – Oct 7

Growing Tips for Oklahoma

Direct-sow in early spring as soon as soil can be worked; seeds need a brief cold period for best germination (refrigerate for a few days before planting if spring arrives quickly). In zones 6+, fall-sow for the earliest spring bloom. Thin to 12 inches; do not over-fertilize — too much nitrogen produces foliage at the expense of flowers. Deadhead to prolong blooming or allow self-seeding for a naturalized colony.

Share this guide:

Frequently Asked Questions

When should I plant Bachelor's Button in Oklahoma?

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

What zone is Oklahoma for planting?

Oklahoma contains USDA hardiness zones 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.