Perennials are plants, usually flowering types, that come back year after year. They differ in when they blossom, but once planted they will burst forth with color every year if treated well. Biennials are similar, but only bloom every other year.
Perennials typically have less vibrant colors than annuals, which last only one year. But they are still often very beautiful. Pale pinks, subtle oranges, delicate yellows and gentle blues and purples can all be found among perennial species. Gardens composed of these flowers, at least in part, often have a very relaxing effect on the viewer.
Perennials come in much more than just flowering types as well. There are many perennials that have only very tiny or no flowers, but are nonetheless very attractive plants. They help to flesh out a garden, and provide the ability to design variety into the layout. Separating bright annuals with non-flowering perennials makes it possible to create an infinite variety of colored shapes and shapely colors.
Foxgloves are a perennial that have long rows of pale orange or pink, bell-shaped flowers along a thick green stalk. A few of these are a delightful addition to any garden, since they are easy to care for and give the garden variety in height and shape.
Hostas are another excellent perennial. Their large, light green leaves make for a beautiful display and, for a few weeks or longer, their lovely white flowers are a wonderful sight. They take very little care, since they get along on very little water. They do very well in partial shade, too.
In the Fall the blooms will die, and later the leaves will shrivel up to thin, light brown vegetation. The transformation is really astounding, considering the width of hosta leaves (nearly a foot) during the height of Summer. Just chop off the dead leaves at ground level before winter and you are all ready to go for the following Spring.
Thyme makes for great ground cover and requires almost no work at all. Sage, too, is terrific for adding not only a pleasant light green color to your garden, but a wonderful fragrance as well. Yarrow will work well interspersed between flowers and ground cover. Just be sure to keep it under control, since it can spread and take over large areas.
Irises have a lovely, large yellow flower on a tall green stalk. They come back year after year and only require a little tug once in a while to pull off the dead, wilted flowers as they bloom and re-bloom.
Bougainvillea bushes are an excellent addition and can be grown in a wide variety of zones. They thrive in the hot weather of California, but tolerate the winters in the Northwest equally well. Drought tolerant and easy to care for, their numerous bright red blossoms make them an excellent choice.
Though the colors are sometimes more muted, there are more perennials than any one garden could possible house. So you have lots of choices for low-effort, beautiful plants that will last year after year.