Tall Blue Planet (Bachelor’s Button / Cornflower)

(Centaurea cyanus)

Tall Blue Planet is a striking variety of Bachelor’s Button, also known as Cornflower, prized for its vivid sky-blue blossoms and tall, upright growth. This classic cottage-garden flower has been cultivated for centuries and is loved for its long blooming season and ability to attract pollinators. With its bright blue petals and easy-growing nature, Tall Blue Planet adds color, height, and biodiversity to garden beds and educational gardens alike.

Plant Specifications

Common Name: Tall Blue Planet (Bachelor’s Button / Cornflower)
Scientific Name: Centaurea cyanus
Plant Type: Annual flowering plant
Height: 30–36 inches
Spread: 12–18 inches
Sunlight: Full sun
Soil: Well-drained soil; tolerates poor to average soils
Water Needs: Low to moderate
Bloom Time: Late spring through midsummer (often longer with deadheading)
Flower Color: Brilliant blue
USDA Zones: Typically grown as an annual in most regions

Growing Tips

• Sow seeds directly in the garden after the last frost, or start indoors early.

• Plants prefer cooler temperatures and bloom best in spring and early summer.

• Removing spent flowers (deadheading) encourages continued blooming.

• Tall varieties may benefit from light support or planting in groups to help stems stay upright.

Pollinator Value

Cornflowers are excellent for pollinator gardens. The nectar-rich blooms attract:

• Bee

• Butterflies

• Beneficial insects such as hoverflies

Their open flower structure makes them easy for pollinators to access.

Interesting Facts

• The cornflower has long symbolized hope, remembrance, and resilience in European folklore.

• The flowers are edible and often used as a natural garnish in salads, desserts, and teas.

• Historically, they grew wild in grain fields—hence the name cornflower.

• The intense blue pigment is one of the most naturally vibrant blues found in garden flowers.

Garden Learning Connection 🌱

In the Thorn Hill Education Center Garden, Tall Blue Planet flowers serve as a colorful teaching plant. Visitors can scan the QR code next to the plant to learn about pollinator relationships, edible flowers, and how annual wildflowers contribute to healthy garden ecosystems.