The Differences Between Perennial, Biennial, and Annual Plants
One of the most frequently asked questions by new gardeners is, "What is a perennial?" or "What is an annual?" Then there are biennials. I'll explain the difference below.
What Is a Perennial?
Perennials will return year after year. This is considered a real bonus, since you don't have to replant every year. A few of these plants have a limited life. An example is a delphinium has a lifetime of just 5 years. Most perennials will provide many years of pleasure. Some reseed themselves. Others survive so long that you'll find old homesteads where the plants have outlived the buildings.
There are hardy and tender perennials. A hardy perennial can survive cold temperatures. A tender perennial may need to be replanted every year in colder zones.
If you'd like a plant to return every year, be sure to check that it is hardy in your zone. Some perennials won't grow in warmer zones. They can't tolerate the heat and sun in those areas. Other perennials will die in the north once the weather gets too cold. So no matter which zone you live in, check for hardiness.
You can find perennial fruits, vegetables and flowers. Some examples of vegetables are rhubarb, asparagus, and strawberries. Perennial flowers include shasta daisies, coneflowers, rhudabeckia,daylilies, peonies and many others.
What Is an Annual?
An annual is a plant that needs to be planted from seed every year. Some will reseed themselves if the conditions are right. You can either plant the seed yourself or purchase them at a greenhouse. Some annuals need to be started indoors in colder climates. A good example is impatiens. These flowers need to be started in January to bloom that summer.
Some annuals can be brought indoors and later started from cuttings. Indoor conditions usually don't have enough light though. I've tried this with inpatiens and coleus. Both worked, but only the impatience did well. You can try with different annuals.
The advantages of these flowers are that many bloom all summer, if you keep the old blooms removed. This is known as dead heading. They are often used in baskets, containers or to fill in the perennial flower bed, since some perennials bloom for a short time.
For a beautiful display of color, plant some annuals this year. A few examples are marigolds, zinnias, petunias, and English daisies. Most vegetables are annuals.
What Is a Biennial?
A biennial takes two years from seeding before it will produce and then it dies. The first year the plant grows a good root system and grows it leaves. The leaves then die off in the winter and the plant goes into dormancy. The second year it will bloom.
Some good examples of this type of plant are hollyhocks, Sweet Williams, and parsley. I have had all three of these plants reseed themselves, so they acted much like perennials. Some biennials will put on bloom the first year and they are foxglove and stock.