The variety of plants that make up the perennial category vary from foliage plants to ground covers to colorful flowers. Each does a different job in your yard. Whether you are looking for a showy flower, such as a day lily, or a beautiful wildlife garden; perennials are the key. The definition of a perennial is a plant or flower that will last many seasons. They are more or less permanent plants in a garden. Its very easy to make sure your garden is in bloom through the seasons with perennials. And by grouping them in clusters of 3, 5, or 7 you get a more intense burst of color when they bloom. Perennials are the skin and bones of the modern garden. They give it structure and shape, and their flowers provide, if a small pun can be forgiven, a perennial delight.