The Hardiest of Hardy Perennials. Generally speaking, a plant is classified as a perennial if it can survive to Zone Above that range, plants become tender perennials or annuals. For the purpose of this article, we will only consider the "hardiest" of
Artemisia: Artemisia has beautiful silver-gray foliage that won’t fade in the hot sun. This hardy perennial is also drought and insect resistant, Height varies by variety and can range from 3 feet tall to just 5 inches.
Rose campion is unforgettable in full bloom because of its abundant hot-pink flowers. But before it puts on its floral show -- and after the flowers fade -- its silvery-gray leaves are ornamental on their own. Note: Rose campion can self-seed abundantly;
Crimson Red Dianthus : Perrenial in full bloom. This was planted in my garden under a gorgeous maple tree. They can take full sun but this one was planted in part sun, fertile soil, and in a zone Enjoy!
'Silver Shimmers' lungwort (or pulmonaria) likes moist, rich, well-drained soil in shade, and grows 1 to 2 feet tall and wide. Give it a site with good air circulation to prevent mildew. It bears blue flowers in spring.