Best Garden Flowers for Color All Summer

If you want to add contrast to a flowerbed or to fresh or dried flower arrangements, this dramatic spiky plant is a great choice. It resembles thistle, but the flower colors blend in more with the prickly blue-green leaves, which are often streaked with silver. Alpine sea holly (E. alpinum) is a deep steel blue, while E. amethystinum is more silvery blue. Miss Willmott's Ghost (E. giganteum) produces especially striking conical flowers, each surrounded by a wreath of silvery, spikey bracts.

Requires full sun; moderate to regular water. Grows as a perennial in zones 3-8.