Knapweed is a genus of hardy perennials that usually have attractive foliage, which is sometimes spiny. They produce thistle-like flowers in shades of lilac, purple, pink and white, which attract bees and butterflies.
There are about 17 species, mainly native to Europe, but with some found in parts of North America. They grow on dry, sandy soils or in rocky areas, often over chalk.
They do best in full sun and require well-drained soil. They are ideal for gravel gardens and naturalistic planting.