Commonly called 'bachelor buttons', centaurea cyanus, this dark maroon to eggplant black variety 'Black Ball' is also aptly named 'Witching Hour'.  Enjoy their most beautiful deepest darkest crimson coloured double blooms all summer long. Bees and butterflies will love them too. Happy in a sunny spot, cornflowers are very easy to grow from seed. They are ideal for borders, or for a cutting garden. They make great for cut flowers and can be easily dried and preserved, maintaining their richly colored shades even when dry. Height: Up to 65cm.