Perennials require less work because you only need to plant them once. Annuals on the other hand have to be replanted every year but they tend to produce more flowers and bloom for longer periods of time than do perennials. If you’re going for less maintenance, perennials are the better choice. If you’re going for looks, annuals are the better choice
Some annuals may come back on their own the following year from seeds from a previous plant; and some perennials may not be compatible with your zone and so will die in the winter and need to be replanted each year. The overall definition of a perennial is a plant that regrows from a root stock that has lain dormant in the ground during the winter; and an annual is a plant that will die at the end of about a year and subsequent plants are new plants grown from seeds.
Perennials are those herbaceous plants that live for more than one season whereas annuals only live for one season. Some might wonder why you would ever want to plant annuals since that would require replanting every year. The big thing that annuals have over perennials is that they tend to produce more flowers and have a much longer blooming period than perennials. Perennials usually bloom in the spring, summer, or even as late as the fall but rarely bloom for an entire season. There are so-called “ever-blooming” perennials that bloom for longer periods of time than is typical for perennials. But the best everblooming plants are the annuals.
The Black-eyed Susan pictured to the right is an example of an ‘everblooming’ perennial: it doesn’t bloom in the spring very much at all but it will bloom for all of summer and for some of autumn if the weather is mild. A list of everblooming perennials is provided at the very bottom of this article for your quick reference.
The reason why annuals produce more flowers and have longer bloom times is because of their life spans only a single growing season. Since the lifespan of an annual is so short, it must try to produce as much offspring (seed) as possible in that growing season, thus increasing the odds that at least a few of their many seeds will germinate and pass on their genes to future generations. Producing lots of seeds requires lots and lots of flowers. In essence, annuals are trying to make the very most out of the short life they have to live. Since annuals only live for a single growing season, there is no ‘growing zone’ assigned to them. The growing zones are used only for perennial plants. The growing zone(s) assigned to each plant tells you in which zones that plant will survive the winter and be able to come back each year. Since annuals aren’t going to live for more than a single growing season, from the last frost to the first frost, there’s no need to assign them to growing zones. So when you go to a nursery, if it has growing zones, it’s a perennial, and if it doesn’t, it’s an annual. To see which growing zone you’re in, check out the USDA growing zone map.
Petunia’s, like the one pictured to the left, are perhaps one of the most popular of the annuals: they produce lots and lots of flowers, bloom all season long, and come in an enormous array of colors.
Perennials have no such push to produce that many seeds (and thus flowers) because they know that they will be around from year to year, so naturally they spend more energy getting established in their environment and concentrate less on producing mass offspring. This prolific flowering nature in annuals is why the gardening professionals who take care of high-profile landscapes almost always use annual flowers instead of perennial flowers.
When planning your flower garden, another point to consider is permanence. Usually you plant perennials because you don’t want to replant every year which can be quite a task. If you’re not worried about constant bloom and you’d rather avoid replanting every year then perennials would suite you well. Just be sure to choose your colors and textures well since your flowerbed is not going to change from year to year. The flower bed pictured to the right is composed of a selection of Corral Bells which have a distinctive dark foliage with contrasting bright flowers raised up on spikes (though not seen in this picture). This is a good example of a more permanent perennial flower bed with season-long interest. A closer look at the Corral Bell foliage is pictured below.
With annuals you can look forward to a new look every year. And of course, you can always mix and match, changing it from year to year. The possibilities are nearly endless.
For those who want to have longer bloom times but would also prefer not replanting every year, I have provided a list of common “everblooming” perennials below. However, I also want to mention that there are now some varieties of everblooming roses, hydrangeas, gardenia (the Jubilation gardenia), daylilies and lilacs (the Bloomerang and Josee lilacs).
One of my wife’s favorite everblooming roses is the Pink Meidiland rose. It’s not one of those over-plush roses where you can’t see into the middle of the flower. It’s an old-fashioned looking rose, and it produces pink blooms quite consistently from spring all the way until the first frost, and the blooms turn into orangey-red rose hips that will stay on the bush most of the winter, adding color nearly year round
Now for other flowers… In the list below, the common name(s) are first and genus name is second in italics. Like many horticultural plants, flowers are also bred many different ways in order to select for certain characteristics. Herein lies an important point: when going to the nursery with a specific plant in mind, be sure to have its genus, species, and even cultivar name in order to guarantee that you’ll get exactly what you want. Common names are not always a sure thing.