Centaurea: Cornflower

Height 30-90cm (1 -3ft)

Planting distance 23-30cm (9-12in)

Flowers early summer to early autumn

Any well-drained soil

Sunny position

Hardy annual

The cornflower is one of our oldest and best-loved hardy annuals, easy to grow and excellent for cutting. Its wiry stems carry sprays of blue, white, pink, purple, maroon or deep red flowers and long, narrow, silver-grey leaves.

Grow cornflowers on their own in a border, or as part of a cottage garden mixture, perhaps with poppies and marigolds.

Popular varieties

The following varieties have been developed from Centaurea cyanus, a cornflower native to Britain.

‘Blue Diadem’ bears large double, dark blue flowers on 75cm (2-1/2ft) tall plants.

‘Dwarf Blue’ has large, blue, double flowers and reaches 30cm (1ft) high.

‘Frosty’ has pink, blue, red and maroon flowers edged white, and white flowers flushed pink. It reaches 60cm (2ft) high.

‘Jubilee Gem’ has large, double, dark blue flowers and reaches 30cm (12in) high.

‘Polka Dot’ produces a mixture of blue and red colours, and stands 38-45cm (15-18in) high.

‘Tall Double Mixed’ comes in shades of pink, red, maroon, blue, mauve and white and reaches 90cm (3ft) high.

The following varieties are developed from sweet sultan (Centaurea moschata), an Oriental species with large scented flowers and grey-green, toothed leaves.

‘Dairy Maid’ has large golden-yellow flowers with fringed petals and prominent centres. It grows to 60cm (2ft) high.

‘The Bride’, pure white and exceptionally fragrant, reaches a height of 40-60cm (16-24in).

Cultivation

Grow cornflowers in any well-drained garden soil, in a sunny site. Sow the seeds in their flowering site in early autumn – under cloches – or in early to mid spring at fortnightly intervals.

When they are large enough to handle, dwarf varieties should be thinned to 23cm (9in) apart, and tall varieties to 30cm (1ft) apart.

Stake tall varieties in exposed positions with twiggy sticks. Dead-head all cornflowers.

Pests and diseases

Petal blight may affect the flowers. Mildew and rust can be a problem.

22. February 2012 by Dave Pinkney
Categories: Featured Articles | Comments Off on Centaurea: Cornflower

Follow

Get every new post delivered to your Inbox

Join other followers: