Centaurea montana is a useful plant for the late spring/early summer border. It has pollinator-friendly, delicate flowers with feather-like petals and was traditionally used to make a bitter tea to treat dyspepsia and as a diuretic. Originating in sub-alpine woods and meadows, the perennial cornflower has been naturalised in the UK since as early as 1597 when the herbalist John Gerard records growing it in his garden. The name ‘Centaurea‘ originates from the Greek ‘Kentauros‘ as the plant’s medicinal properties were first discovered, according to Pliny, by the mythical character Chiron the Centaur.
Centaurea as a genus encompasses between 350 and 600 species of thistle-like plants in the family Asteraceaea. Centaurea montana is also known as ‘perennial cornflower’, ‘great blue-bottle’, ‘mountain cornflower’, ‘batchelor’s button’, ‘mountain bluet’ or ‘mountain knapweed’, with ‘montana’ referring to the sub-alpine regions in which the plant originates.
Centaurea montana does have a tendency to be an enthusiastic garden plant – it needs to be controlled by removing unwanted sections as it spreads out, but the named varieties are much better behaved in my experience. Although I love the colour of ‘Jordy’ with its deep plum purple flowers, I find they can get lost in a border when viewing it from any distance away. They work well as a cut flower and, as with all Centaurea montana, if picked regularly the plant will continue to produce flowers for a long period. My favourite variety is ‘Amethyst in Snow’ for its ability to create delicate highlights in a border, its contrasting amethyst eye, set in the snowy white petals and the silver-green foliage. ‘Amethyst in Snow’ was discovered in 2002 by Dutch seedsman Kees Sahin and it tolerates a little shade more happily than other varieties. It is supposedly the first bicolor knapweed and is similar (possibly identical) to another variety called ‘Purple Heart’.
For a fully white flower there’s Centaurea montana ‘Alba’ and ‘Gold Bullion’ has blue flowers against chartreuse yellow foliage. ‘Carnea’ has soft pink flowers and ‘Violetta’ deeper violet purple flowers. This varied colour range means Centaurea montana has the ability to be combined with soft pastel planting or included in vibrant schemes with deep reds, oranges, blues and purples. A versatile garden plant, Centaurea montana ‘Amethyst in Snow’ combines elegance with a stout heart.