Basically there are three types of flowers.

Annuals, plants for quick color and that are only meant to for the season they are planted.

Perenials, those that come back year after year. Growing bigger, more lush, and can be depended on for long life and consistent color in your yard.

Bi-annuals, flowers that are set out one year, but do not actually bloom until the following year. Now alot of people are confused by Bi-annuals because they buy them from the nursery as an established potted plant. What they do not realize is that they have the one years growth already on them when you buy them. Like a foxglove, when you purchase them and set them out, they will bloom the same year. But if you start them from seed, you will not get a flower until the following year. So for continuous growth, you must plant year after year. Some plants like the foxglove will sometimes reseed themselves. But the only problem with counting on this, they do NOT always come up where you want them.......it never mattered to me, whereever they came up was always fine with me.

Something I discoverd about perenial flowers,( by my having lived in both cold country and in the south of California, in Garden Grove, where it never got below 40 degrees), the plants that are considered perenials up North where it freezes will not work for you as a perenial in the south where it doesn't freeze. An example is the beautiful and stately delphinium. They grow stout, tall and beautiful, and become a garden focal point in the Northern cold weather garden. But in Southern California, where it never freezes, they will continue to grow, until they just fizzle out. And the next year, they do not come back. They just rot. They must have the cold ground to place them into dormancy for the next season. So if you live in the South, say San Diego, just plan on buying them every year. I found that they really did not do all that well for me anyway, where as in Lake County where the weather drops to about 27 degrees in the winter, the stalk would grow stout and the plant could reach 5 feet tall. Each year they came back prettier and stronger. One thing I discovered about delphiniums, they like cool feet, which means, the plant must be in the sun, but the roots like shade. This is best accomplished by planting low growing plants near the base of the delphiniums.