If you live in a hot, dry climate, choose perennials that thrive in those conditions. Here, Heliopsis and coreopsis have roots in the American prairie, so you know these flowering beauties will keep on blooming even though temperatures and rainfall fluctuate. There's no need to coddle either one.
The Hardiest of Hardy Perennials. Generally speaking, a plant is classified as a perennial if it can survive to Zone 7. Above that range, plants become tender perennials or annuals. For the purpose of this article, we will only consider the "hardiest" of hardy perennials, plants that are hardy to Zones 4 and lower (or higher in latitude). The plants on this list are definitely tough enough to survive your area's worst winters.
UPDATED Infographic: Want more butterflies in your yard? Plant the nectar plants they love! Here's a great list of butterfly-attracting annual and perennial plants — including those needed for butterfly larvae. #garden #gardening