About
Centaurea cyanus 'Blue Ball' is an annual cornflower that reaches a height of about 80 cm when in bloom. It features elongated, grey-green foliage. Throughout the summer, it produces abundant double flower-heads in a vivid cobalt blue.
About the genus
Centaurea includes annuals, perennials, and subshrubs, characterized by simple or pinnately lobed foliage and prominent flower heads resembling thistles, frequently featuring enlarged outer florets.
Growing conditions
- Sunlight
- Full sun
- Soil type
- Chalk, Loam, Sand
- Soil pH
- Acid, Alkaline, Neutral
- Soil moisture
- Moist but well-drained, Well-drained
- Aspect
- South-facing, West-facing
- Exposure
- Sheltered
- UK hardiness
- H6
Plant details
- Plant type
- Annual Biennial
- Habit
- Clump forming
- Foliage
- Deciduous
- Height
- 0.5-1 metres
- Spread
- 0.1-0.5 metres
- Time to full height
- 1-2 years
- Suggested uses
- Cottage and informal garden, Patio and container plants, Wildflower meadow, Wildlife gardens
Care notes
- Cultivation
- Grow in well-drained soil in full sun
- Pruning
- Deadhead regularly to prolong flowering
- Propagation
- Propagate by seed sown in-situ in spring or autumn
- Pest resistance
- Generally pest-free
- Disease resistance
- May be susceptible to powdery mildews