Annuals are the "color stars" of the garden. Plant them where you want easy-care flowers to bloom all summer long. Annuals are plants that grow and bloom for one season. Some of them -- like marigolds -- grow, bloom and go to seed all in one season. Others -- like geraniums -- are really perennials that just aren't hardy enough to survive the winters.
The delightful colors of annual flowers are enhanced by Colorado's warm days and cool summer nights. This combination of unique weather conditions gives us a huge range of types and varieties of annuals to choose from. You can plant most annuals any time during the spring, summer or fall, and they'll bloom continuously until the first frost. Most annuals are planted after the last frost. Of course, the time the first frost occurs varies within Colorado, but it generally occurs between the tenth and fifteenth of May along the Front Range.
By learning a little about different flowers, you'll find that some--like petunias--tolerate cool conditions better than others, and some--like pansies--even survive frost. Some pansies can be planted in the fall to achieve color all fall, winter and spring. Others -- like vinca -- are heat lovers only.
When you go to the garden center or nursery, or look through a seed catalog, you'll see there are hundreds of annual flowers from which to choose. Some annuals that do well in the sunny areas of Colorado are cleome, zinnia, marigold, flowering tobacco, sunflower and snapdragon. Annuals of medium height that perform well in sunny locations are dahlia, geranium, marigold, snapdragon and Victoria salvia. Some short, sun-loving annuals include petunia, marigold, vinca, verbena, gazania, alyssum and portulaca. Some shade lovers include impatiens, begonia, lobelia and coleus. All come in several colors and heights. Be sure to read the labels or ask a salesperson if you're unsure whether a particular plant is right for your situation.
When you want to brighten up that dark corner or just put some pizzazz in your landscape, annual flowers are stars that will shine all summer long!
For more information, see the following Colorado State University Extension fact sheet(s).
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Updated Tuesday, November 19, 2013