Centaurea cyanus Black Ball

Centaurea cyanus 'Black Ball' is a relatively recent variety of Cornflower or Bluebottle, distinguished by its beautiful dark pompom-shaped flowers. With a deep purple hue and chocolate undertones, they appear almost black under a cloudy sky, adding a touch of drama to any flower bed. Highly decorative in large clumps, this annual plant blooms for months if faded flowers are removed. Sow this cornflower directly in place, in March-April, to quickly and easily create a countryside-style decor, mixed with poppies, candytuft, borage, and cosmos.

Cornflowers belong to the Asteraceae family. Centaurea cyanus is an annual herbaceous plant native to Europe and Northern Asia, long considered an invasive weed in cereal crops, but one of the most beautiful wildflowers in our regions. The 'Black Ball' cultivar is one of the many horticultural improvements derived from this species. It forms an upright clump with branching stems, reaching a height of 75 cm (29.5 in) and a width of 30 cm (11.8 in), bearing very narrow and long greyish-green leaves. It blooms from June to August, displaying highly double inflorescences, 4 cm (1.6 in) in diameter. The ligules (or petals of the corolla) are dentate at their tips, of a deep purple-brown colour. The centre of the inflorescence consists of black florets. These flowers are highly attractive to bees and nectar-feeding insects.

Centaureas enchant flower beds and borders, where they create remarkable spots of colour. The Cornflower and its varieties bring the charm of the countryside to your garden. Sow centaureas in slightly wild flower beds: they will be sublime in the company of ornamental grasses like Stipa tenuifolia, Stipa pennata or barbata, Mulhenbergia capillaris and poppies, with pink or white Love-in-a-mist, Californian poppies, purple centaurea, Briza media with its small white plumes, and many more. The almost-black pompoms of 'Black Ball' contrast beautifully with those of the white variety, 'The Bride'. The edible flowers can be used to decorate summer salads. Centaurea cyanus is also an excellent cut flower.