Giant Knapweed

Centaurea macrocephala, often called Giant Knapweed, is a bold and imposing perennial that makes a real statement in a sunny border. It produces large, thistle-like flower heads that are a bright, golden yellow, encased in distinctive papery, brownish bracts that look slightly like scales. These heavy blooms are supported by thick, unbranched stems that can reach up to 150cm in height. The foliage is coarse, mid-green, and slightly hairy, forming a substantial clump at the base. Native to the Caucasus, it is perfectly hardy in the UK and thrives in any well-drained, fertile soil. It is a fantastic plant for attracting pollinators and the spent flower heads remain attractive well into autumn, providing food for birds. Due to its size and weight, it may require staking in more exposed gardens. It is a brilliant choice for adding height and late-summer colour to a large perennial border or a meadow-style planting.

Sun: Full sun.

Soil: Well-drained, fertile soil.

Hardiness: H7 — below −20°C.

Flowering: Jul, Aug.