Perovskia atriplicifolia 'Blue Spire' has fall interest with its purple blooms. This plant will go well with several other purple features of the landscape. I have always been fond of this silvery foliaged plant.
'Big Blue' Sea Holly for sunny garden, deer-, rabbit-, and drought-resistant perennial shows off silvery foliage and iridescent silvery-blue flowers in midsummer...wonderful cut flower and prime choice for butterfly gardens. Name: Eryngium 'Big Blue' Full sun well-drained soil Size: To 30 inches tall and wide Zones: 4-9