Flowers, like herbs, were probably first cultivated for their medicinal purposes rather than for their beauty. Flowers grow on vines, like honeysuckle, or on bushes, like roses. They include perennials, such as delphiniums, or annuals, like zinnia. Perennials are plants that grow for a season, flower, die back and then come back at the beginning of the next growing season. Annual flowers grow from seed for one season, blossom and then die.
An island flower bed is surrounded by a lawn, ground covering or "hardscape," such as a patio. It's viewable from all sides. Tall flowers are planted in the middle, surrounded by flowers that are grow shorter as they reach the edge of the island. If the island is surrounded by a patio, thought must be given as to how the bed will be watered. It may also be necessary to plant heat-tolerant flowers.
Flower beds can border a building, walkway, driveway or fence. The beds should be at least three feet wide, as narrower beds look out of proportion. The flowers are tallest in the back and progressively get shorter to the edge of the bed. This is for two reasons. The tall flowers won't block the sunlight from reaching the shorter flowers and won't block the shorter flowers from being visible.
Under a tree or up against a building, shady areas are challenging to landscape. There are many types of flowers that not only thrive in the shade but prefer it. These include impatiens, begonias, hostas, astilbe and fuschia. When planting under a tree, make sure the flowers are sufficiently watered and fed. Trees are greedy feeders and thirsty.
If you've ever taken a walk in the woods and stumbled on a meadow filled with wild flowers, that's the feeling a naturalized flower bed gives you. The flowers look as if they've grown by chance. A naturalized bed doesn't have to be planted with wild flowers, but it would be appropriate. The flowers appear to be randomly distributed. Many naturalized beds reseed themselves and come back year after year.
Think of the gardens of an English country manor with the sculpted hedges, manicured lawns and carefully groomed flower beds---that's what a formal flower bed resembles. Formal beds are usually planted with just a few species of flowers that are coordinated by color, bloom time and height. The flowers should be deadheaded (spent blossoms removed) regularly to keep up the appearance of formality.