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The difference between annuals, perennials and biennials

By By Amelia O’Brian / horticulture columnist
March 7, 2004
Dear Gardener: Should I have covered up my pansies during the recent dip in temperatures? I didn't and they are looking pretty rough.
Dear Reader: I strongly recommend covering pansies when the temperatures drop into the middle to low teens, especially when the temperature doesn't rise very much above that during the day. Once the temperature rises above freezing the covering should be removed. I use tobacco cloth (Remay) to cover pansies and any other tender plants. If you can't find tobacco cloth, an old sheet should work.
Note: If there is snow covering the pansies, it will work as an insulator and protect them from the low temperatures. So, there is no need to cover the pansies if they are already covered with snow.
Dear Gardener: Is there any difference between violas and pansies besides there size?
Dear Reader: The obvious difference in violas and pansies are their size. A more important difference in the garden, though, is the fact that violas will reseed themselves and return the next year. Pansies will not.
Dear Gardener: You are always mentioning annuals and perennials. I am new to gardening and not familiar with the terms. Could you explain what these words mean?
Dear Reader: Thanks for asking this question. I am sure many others have wondered what they mean as well. The words annual, perennial, and biennial are used to describe the life cycle of plants.
Annuals live only one growing season. This means they germinate, develop leaves and flowers, set seed, and then die all in one year. Annuals vary in different hardiness zones. Plants that may be perennial in one zone can be quite possibly annuals in another zone due to lack of cold or heat hardiness. Examples of annuals in our area are pansies, impatients and marigolds.
Perennials on the other hand survive from year to year. They typically have a dormant period during one of the seasons, usually winter. Some examples of perennials include dianthus, daylilies and yarrow.
Biennials are a group unto themselves. They only develop foliage the first year. Then after a dormant period, they rejuvenate their leaves, flower, and produce seed. After seeding, they usually die. Examples of biennials are foxgloves and hollyhocks.
Dear Gardener: I recently saw a flower on a book cover, but could not find out its name. I am hoping you can tell me what it is and how to grow it. The flowers were born on stalks appearing to be about 2- to 3-feet high. One white flower shaped like a goose's head and beak topped each stalk. Do you have any idea what this plant is?
Dear Reader: Sometimes plant identification can be difficult without a picture, but I am going to venture a guess to your inquiry. I am fairly certain that the plant you like so much is gooseneck loosestrife (Lysimachia clethroides).
It is a perennial that can reach about 3 feet in height and 2 feet in width. It prefers a slightly moist soil if planted in full sun. The white flowers bloom in the summer. Foliage may color a bit in the fall.
I really like gooseneck loosestrife too. But be aware it can be invasive, so I suggest dividing the clumps regularly to control it.
Amelia O'Brian is a native of Meridian who earned a horticulture degree from Mississippi State University. If you have a gardening question, e-mail her at Ameobrian@aol.com.

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