Thistles or Cirsium may be best known for their showy purple flowers and pink flowers, in addition to their prickly foliage. But these perennials are also important for pollinators, as well as a ...

Upright stems carry small, grey-blue, thistle-like flowers that sit on a broad, spiny ruff that adds enormously to their impact. ‘Picos Amethyst’ (15-18in) has dark amethyst blue flowers that ...