Bachelor's Button, Cornflower 'Blue Boy'

Centaurea cyanus

Family: Asteraceae (ass-ter-AY-see-ee) (Info)
Genus: Centaurea (sen-TAR-ee-uh) (Info)
Species: cyanus (SY-an-us) (Info)
Cultivar: Blue Boy



Foliage Color:


Bloom Characteristics:

This plant is attractive to bees, butterflies and/or birds

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Where to Grow:

Unknown - Tell us


24-36 in. (60-90 cm)


9-12 in. (22-30 cm)


Not Applicable

Sun Exposure:

Full Sun



Bloom Color:

Medium Blue

Bloom Time:

Late Spring/Early Summer

Mid Summer

Late Summer/Early Fall




Other details:

Unknown - Tell us

Soil pH requirements:

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

Patent Information:


Propagation Methods:

From seed; direct sow outdoors in fall

From seed; winter sow in vented containers, coldframe or unheated greenhouse

From seed; sow indoors before last frost

From seed; direct sow after last frost

Seed Collecting:

Collect seedhead/pod when flowers fade; allow to dry


This plant has been said to grow in the following regions:

North Little Rock, Arkansas

Berkeley, California

Irvine, California

Long Beach, California

Longmont, Colorado

Cordele, Georgia

Chicago, Illinois

Hinsdale, Illinois

Dubuque, Iowa

Peosta, Iowa

Brookville, Kansas

Sapphire, North Carolina

Cincinnati, Ohio

Painesville, Ohio

Denton, Texas

San Antonio, Texas

Chimacum, Washington

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Gardeners' Notes:


On Jul 13, 2015, crayondoom from Fargo, ND (Zone 4a) wrote:

While I love the blue color this cornflower provides it is definitely not something for the front of the garden; it grew even taller than I expected. The bees love it though, so I will be planting this again next year in a different spot.


On Nov 25, 2008, CurtisJones from Longmont, CO wrote:

From your friends at Botanical Interests: Annual. Summer bloom. 20" - 24" tall. Full sun. Drought tolerant. The sky blue flowers of this tall plant are attractive as cut or dried flowers. Will "naturalize" - seed drops quite readily and produces another crop of flowers. Seed must have darkness to germinate. Sow at depth of 1/4". Seed to 1" apart and thin to 6" - 8" apart. Plants have fewer flowers when grown in rich, overfertilized soils. The worse the soil, the better! An additional fun story: When Napoleon forced Queen Louise of Prussia from Berlin, she hid her children in a corn field and kept them entertained and quiet by weaving wreaths of Cornflowers (Bachelor Button). One of the children, Wilhelm, ultimately became the emperor of Germany. Remembering his mother's bravery, he made th... read more


On Mar 4, 2007, berrygirl from Braselton, GA (Zone 7b) wrote:

Brought to America from Europe in the 17th century and known to have been cultivated by Thomas Jefferson at Monticello. Plants will bloom throughout the growing season. Well maintained strain with all blue flowers. Extremely easy to grow and dries well. Self-seeding hardy annual, grows 2-3 ft tall.