An Introduction to Annual Flowers

Annuals flowers complete their growing cycle, going from seed to seed, in one year. Gardeners use annuals for a splash of summer color in flowerbeds, for cutting flowers and in container gardens. Annuals are inexpensive and easy to grow, and best of all you can change the look of your gardens each year.

True Annuals or Treated as Annuals?

Many of the flowers that we know and love are true annual flowers, including marigolds, zinnias and sunflowers. Others are actually tender perennials that would continue growing if frost didn't kill them. These tender perennials are usually treated as annuals in climates with cold winters, although some can be overwintered inside. A few examples of tender perennials that we treat as annuals include geraniums, petunias, impatiens, begonias and coleus.

Many new annuals and tender perennials are coming on the market, so you don't have to stick to the same old boring petunias. Some old-fashioned cottage garden annuals are getting a makeover by plant breeders to introduce more disease-resistant and longer-flowering plants. The beauty of annuals is that they are generally inexpensive; you can try new things and if you don't like them, you can replace them with something else next year.

Growing Annuals from Seed

Many annuals can be grown by directly sowing the seed in the ground. They grow so quickly that you will have blooms in a few weeks. You can get a great range of annual plants this way for very little money. Some annuals need to be started inside a few weeks before the last frost for earlier flowers.

Each variety of seed needs different conditions to get off to a good start. Follow the package instructions for sowing seed. When annual seeds are sown inside, you should always use a sterile seed starting mix and clean containers. This helps prevent dampening off, a fungal disease that kills seedlings.

Choosing Annuals at the Garden Store

Many gardeners choose to buy annual plants from a garden center. Annuals are now available for a much longer period, so you can buy them to replace plants that have finished blooming or to make a new container garden later in the summer.

In the spring, many annuals are sold in cell packs in groups of four or six. These are the plants most likely to become stressed by their confined conditions. The best annuals in cell packs will be short and stocky, with dark-green foliage. We all like instant color, but avoid annuals in cell packs that are already in full bloom. These are often stressed and don't adjust well to garden conditions.

Slide one of the annuals in the cell pack out of its pot to look at the root system. Healthy roots are white or pale yellow. The roots will generally fill the cell pot. If they are coming out of the bottom, the annual has been sitting a while and may be stressed.

Annuals planted in larger square or round pots have more room for their root systems and are the best plants to buy later in the garden season. They may be blooming, but if they have been well cared for, they will be less stressed than plants in cell packs.

Planting and Caring for Annuals in the Garden

If you had to buy annuals blooming in cell packs, pinch off the flowers before you plant them. They will set new flowers soon and will have time to get their roots established before using energy to flower. Many annual flowers are sensitive to frost. If you plant them too early, you'll need to cover them if a frost threatens.

Have you ever cleaned up the garden in the fall and pulled those annual flowers out of the ground complete with the little square root ball that they came out of the cell pack with? Those plants never rooted properly and couldn't reach their full potential. Prepare your planting spot by loosening the soil and removing any weeds or rocks. Work a little slow-release flower fertilizer into the planting area according to label directions.

As you take each annual plant out of the cell pack or pot, look at the root system. If there is a wad of roots wound up at the bottom, gently pinch off the very bottom of the root ball. Then lightly squeeze the root ball in your hand to loosen the sides, and slightly flare out the roots as you plant the annual. This gets the roots moving out into the soil instead of continuing to wrap around in the hole.

Water your annuals well after planting. Annuals in containers may have to be watered twice a day in hot, sunny weather. Most types of annuals need regular watering to bloom well. Annuals use a lot of energy producing all those flowers, and they benefit from a dose of slow-release fertilizer every six weeks.

Annuals bloom so they can reproduce. When flowers get pollinated and set seeds it sends a signal to the plant that its job is done and it can die. That is why it's important to remove flowers as they wilt, before the seed they are trying to make gets very big. This is called deadheading. Some newer varieties of annuals are bred to ignore this signal, and deadheading isn't as important. It still makes the plants look better to remove dead flowers when you can.

If annuals stop blooming and get lanky and straggly looking later in the season, try something drastic. Chop them off about six inches from the ground. Water well and in a few weeks they will usually be blooming again. You may want to do this to every other plant, or randomly, so all the plants don't rest at the same time.