This is an easy to grow perennial flower for a sunny aspect, which flowers from early summer to well into the autumn. The clumps of Knautia (pronounced ‘naughtier’) do get large and sprawl about, so give them plenty of room. The crimson pompom flowers are a big hit with bees and butterflies and the seed heads are loved by the birds. It self-seeds prolifically and I often replace the large clumps with younger specimens. It can be affected by powdery mildew, however I simply cut back the stems and allow to re-grow.