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Differences between annuals and perennials

Botanically speaking, annuals are plants that complete their life cycle within aPhoto of Impatiens and Coleus year. The seeds germinate, the plant matures, flowers and dies in one year. Only the seeds continue the species from one year to the next. Since they complete their life cycle in one year you will have flowers and mature foliage relatively quickly. Bringing annuals indoors for the winter will not help; their life span is no longer than one year. Examples of annuals include marigolds, pansy, impatiens and petunias.

Daylily photoPerennials
Perennials are plants that need at least two years to complete their first life cycle. They usually germinate and produce vegetative growth the first year. In the second and subsequent years they'll produce flowers and seeds. Perennials go dormant (die back to the ground) after flowering, but reappear the following season from the same root stock. Examples of herbaceous perennials are peonies, Shasta daisies and daylilies.

Somewhere in-between
Within these two broad groups there are several sub-categories and some plants which blur the lines. Some plants are categorized as "short lived or tender perennials" such as thread-leaf coreopsis - they may only reappear the following season if planted in a protected space or only for a few years. Some plants like dianthus (pinks) will flower in their first year but will also reappear from the same root stock. Geraniums are actually perennial plants in warmer climates but are grown as annuals here because they grow and flower so quickly. Some annuals, like Cosmos, are so reliable at reseeding themselves it's hard to tell they aren't perennials. To further complicate the matter, some plants are classified as biennial - plants which require two years to complete the life cycle and then die. Examples of biennial plants are hollyhock and foxglove.

When I plant container gardens for the Colorado summer, I use annuals. They grow and bloom fast for our short growing season. Their compact roots are better suited to containers and they can be placed in decorative containers which can be emptied and protected for the winter.

If you've ever been confused about a plant's classification, that's because it is confusing!

Stephanie Selig
tel: (970) 988-3808

Looking Forward to Summer

Anxious to get your planters filled with flowers? Get your spring planting scheduled now!
(970) 988-3808

The planting schedule begins May 17. Don't be tempted to set out any of your tender plants too soon! The average last frost-free date in northern Colorado is May 15.

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Take it Outside

Your lawn will appreciate some attention as it is warming up. Core aerating improves air flow in our heavy soil and encourages root growth. Fertilizing is usually a good idea, too. However, if your lawn was healthy and lush last year fertilizing may not be necessary. The only way to know for sure is a soil test. Contact CSU's extention office for more details at 491-6281.

Vegetable Gardening

It's time to turn all the soil in your vegetable garden and mix in some aged compost. If you haven't started them already, you can definately plant your lettuce and peas!