Petunias have many uses in the landscape. Edge a perennial border with the more compact multifloras or floribundas. Plant them on the ends of vegetable beds, especially those that contain trellises of beans or cucumbers--they'll fill the ground-level space with color that looks particularly attractive against the vegetables' green foliage. Put petunias in mixed plantings in window boxes or in containers attached to the deck railing: the cascading or spreading types combine well with salvias and geraniums; grandifloras mix well with sweet alyssum, ivy-leaved geraniums and portulaca.
Petunias make excellent cut flowers; like pansies and zinnias, the more you cut, the more the plants seem to produce. Because their stems are somewhat lax and their leaves are sticky, the flowers are best cut with short stems. Place them in small vases or flower rings, where they'll last for four to six days. As a cut flower, they may add fragrance to a room. The flowers can be pressed, either whole or with petals taken apart and pressed individually.
Don't use the blooms as an edible decoration, because the plants are toxic, as many members of the Solanaceae family are.