Centaurea nigra – Black Knapweed also known as Common Knapweed or Lesser Knapweed. In our experience Black Knapweed is one of the most competitive of all wildflowers and for that reason is perfect for introducing into fertile soils where it will often compete and grow well amongst tussocky grass. It also grows well on open ground and is well suited to clay and loam soils where there is plenty of sunlight.
Black Knapweed is a tall plant with a mauve flower that appears from June to September. Plants harbour a wide range of insect life such as Bees, Butterflies and Ladybirds and are often visited by birds such as goldfinches in search of the seeds.
Black Knapweed looks best growing with other summer flowering plants such as Oxeye daisies, Musk Mallow, Meadow Cranesbill and Field Scabious.
BLACK KNAPWEED Seeds
How to grow Black Knapweed from seed:
Sow Black Knapweed seeds in spring or autumn either outside where it is to flower, or in seed trays and cover lightly with compost. It is usually easy to germinate and the seedlings, which are quick to develop, can be pricked out and grown on, for planting out later in the year.