Hardy geraniums and phlox are two easy to care for purple perennials. Both types of perennials do well in both full sun or partial shade.
Hardy purple geraniums bloom from the end of spring through early summer, but will bloom again in the fall if the plants are cut back, notes Martha Stewart. Purple phlox plants bloom through the summer months and into autumn. Phlox is often used as a cut flower, to add a touch of pastel color in flower arrangements. Mildew-resistant phlox plants can be purchased as easy-care perennials to be planted in areas with high humidity. Other easy to care for purple perennial flowers include irises, asters and hosta lilies.