Scientific:
Centaurea cyanus (Synonym: Leucacantha cyanus)
Common: bachelor buttons, blue bachelor buttons, corn flower, garden cornflower
Family: Asteraceae
Origin: South England, Whales, northwestern Europe and the Mediterranean region of southern Europe where native populations are diminishing, but in contrast it has naturalized across nearly all of the continental United States and Canada.
Pronounciation: Cen-TUR-e-a sigh-AN-us
Hardiness zones
Sunset All (warm or cool season annual depending on zone)
USDA All (warm or cool season annual depending on zone)
Landscape Use: Accent plant for flower borders
Form & Character: Upright, open, cool, informal, free spirited.
Growth Habit: Rapidly growing herbaceous annual branching to 2- to 3-feet tall.
Foliage/Texture: Leaves are covered with small white hairs causing the plant to have a blue-gray appearance, older leaves are lyrate-pinntified or narrowly oblanceolate, entire or broadly serrate, young leaves a linear to linear lanceolate, highly pubescent, sessile;
medium texture.
Flowers & Fruits: Ray flowers to 1 inch in diameter, intense blue color (rarely pink), arranged in flowerheads called "capitula" with a ring of several large, spreading ray florets surrounding a central cluster of disc florets; fruits are elongated pappus bristles.
Seasonal Color: Bachelor buttons bloom heavily during the cool season in Phoenix. Many flower colors are available such as pink, light blue, medium blue,
blue-violet, white, and off white.
Temperature: Avoid high heat of western exposures.
Light: Full sun to partial shade.
Soil: Tolerant, but in Phoenix does best in organic amended soil that is well drained.
Watering: Regular supplemental water is necessary in Phoenix.
Pruning: Remove spent flowers.
Propagation: Seed; fresh seed germinate quickly in 7 to 25 days at 60o to 70oF with no additional treatment.
Disease and Pests: None
Additional comments:
Bacheklor buttons grows quickly and blooms heavily. This is a surprisingly easy plant to culture in flower borders in Phoenix as a fall, winter or spring annual. It's not for summer though (way too hot in Phoenix). Overall, bachelor buttons is an outstanding performer for mixed flower borders whether your preference is for cutting or admiring. It is attractive to bees, butterflies and/or birds. Sadly, it is not as commonly seen today in Phoenix landscape gardens as it used to be back in Grandma's day.
There are many named cultivars including:
Miscellaneous factoids: The nickname "cornflower" comes from the fact that the plant grows wild in the grain fields of southern Europe. It has naturalized throughout much of North America. The blue flower pigment is protocyanin, which in roses is red. The flowers are used traditionally in European phytotherapy to treat eye inflammations and contain polysaccharides (galacturonic acid, arabinose, glucose, rhamnose, and galactose) with anti-inflammatory properties.
