Annual, biennial, perennial: What does it all mean for plants?

Published 12:00 am Friday, September 17, 2004

When selecting plants at your local nursery, each is labeled as an annual, biennial or perennial. What’s the difference? Lots. These words describe the life cycle of the plants and let you know how long to expect them to flourish in your landscape.

The definition of an annual describes &uot;a plant whose entire life cycle, from germination to seed production through death, takes place within one year.&uot; Hardy annuals or cool season annuals are those that can tolerate some frost. Half hardy annuals or warm season annuals are those that should be planted when all danger of frost is gone.

Annuals are generally thought of as an inexpensive way to add color in the garden over a particular season. The many uses and attributes of annuals are what make them so valuable in the landscape. Varied textures, fragrance, flower color and growth habit give annuals the ability to transform any garden from dull to spectacular in short amount of time.

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Often we see entire flower beds devoted only to colorful annuals and many gardeners reserve special areas in their borders especially for these vibrant flowers. The obvious advantage is that the plants can be changed out several times within a year to create entirely different displays.

In the Miss-Lou, it’s almost as if we have three seasons for annual color. The initial planting of the year is for spring and summer color. The next is in the latter part of the summer to replace any plants that did not fare well through the hot months and to insure that the flower beds will be dazzling in the fall.

These plantings are followed by another in which cool season annuals are set out for winter and early spring bloom. Not only do annuals flower freely over several weeks or months, they also provide the opportunity to experiment in the garden by changing color schemes from season to season.

Biennials are plants which require two seasons of growth to flower. The first season is spent producing leaves. After overwintering they produce flowers the next year. In the Miss-Lou this can be misleading since most biennials can actually be started from seed and flower all in one season due to our extended growing period.

Foxglove, hollyhocks, and some dianthus are biennials but we are able to grow them as annuals here if planted at the right time therefore saving us an entire year of waiting for their beautiful blossoms.

Perennials are &uot;nonwoody plants that live for two or more years. Most are herbaceous, dying back in the fall to ground level, or to a woody base, and sending up new growth in spring.&uot; Many evergreen perennials are also well suited for the Miss-Lou.

The favorite of southern gardeners, perennials are available in a vast array of color, shape, form, texture and fragrance making them a wonderful long lasting addition to the landscape. There are perennials that are suited to any situation be it dry, wet, sunny, shady or anything in between. The diversity and reliability of perennials adds a lasting source of pleasure to any garden, large or small.

When choosing perennials or any type of plant for your landscape, make sure that they are suited to your individual specifications. Requirements vary from one plant to another, so it is important to know what your growing conditions are. Proper attention given to light, garden soil, microclimate and exposure will give your plants a better chance to flourish and probably cut down on some of the maintenance, too.


Traci Maier