Perennials are defined as flowers that have more than one growing season. They grow and bloom during the spring and summer, die back in the fall or winter and return in the spring. The number of years that the flower can return for varies greatly by the flower. Some perennials are short-lived, returning for only a few years, while some are long-lived, lasting several years. While perennials have a shorter bloom time than annuals—a few weeks as opposed to a few months—they more than make up for this in their ease of care. Some of the most popular perennial flowers for planting are carnations, hosta and yarrow. Carnations grow well in full sun. Yarrow can handle intense sun that would kill many other flower types. Hosta is quite the opposite, being a shade-loving plant.