Perennials can be used in many different ways in the garden. Sun-loving ornamental grasses and brightly blooming flowers such as purple coneflower, black-eyed Susan and goldenrod are gorgeous in large amounts. Shade-loving perennials such as host and ferns can be mixed with smaller trees, flowering shrubs, evergreens, vines and bulbs in a layered garden. Perennials can be used to cover the ground under a tree or to hold a hill that is too steep for mowing. They can be grown in pots or used to mark an entryway, to brighten an outdoor area or to mask a bare spot in the garden.