Annuals Vs. Perennials

Both annuals and perennials have uses in the flower border.

Annuals are plants that live for one growing season. Perennials live from one year to the next. Even if perennials lose their leaves and go dormant in the winter, they grow and bloom the following year. Planting a bed of perennials only has to be done once, while a bed of annuals will have to be replanted each year.

Cost

Since perennials take longer to flower, nurseries and plant growers have to keep them growing for more than a year before they sell them. That extra time means they cost more. A 1-gallon gardenia, for example costs between $6 and $10 as of 2011. A 1-gallon petunia, an annual, costs about $3. Annuals are often sold in flats and in six packs while perennials are not. The seeds of both cost about the same. Choose a few perennials, and then fill in the garden bed with annuals that grow and flower quickly.

Hardiness Zone

Since perennials live from year to year, the variety you choose must be adapted to your U.S. Department of Agriculture Plant Hardiness Zone to live through the winter and bloom the next year. That's not a problem with annuals, as they only live for one growing season. With annuals, consider the growing season's length. In lower Hardiness Zones, the growing season is usually shorter. If that's the case where you live, start annuals from seeds about two months before the average date of the last frost in spring. Transplant into the garden when the weather warms up.

Cool and Warm Season Flowers

Certain perennials, such as peonies, need a cold dormancy period. Others, such as canna, won't tolerate cold weather. Choose perennials that do well in your area. Hydrangeas need moist soil and cool temperatures. Some annuals grow better in cooler weather before the summer heat arrives. They're called cool-season annuals and include pansies, snapdragons and stock. Other annuals thrive when the daytime temperatures are 80 degrees and above. These are warm-season annuals and include marigolds and zinnias.

Fruits

Most fruits are perennials. Although strawberries will bear fruit the first year, most other perennials, such as raspberries and blackberries, provide a better harvest after the second year. Fruits that are annuals include watermelons, cantaloupes and other melons.

Vegetables

Asparagus, tomatoes and artichoke are all perennial vegetables. Tomatoes are frost tender and won't live from year to year in colder climates. Other than tomatoes, these vegetables take a year or so to get established and shouldn't be harvested until after the second year. Most vegetables are annuals. Even in warm climates, they start die in the fall. Cool season annual vegetables include leafy greens, lettuces, peas, cabbage and broccoli. Warm season annual vegetables include corn, beans and peppers.

References

• Oregon State University: Ready Your Perennial Vegetables for Winter's Wrath; Carol Savonen
• University of Illinois Extension: Tomato
• "The Country Garden"; Charlie Ryrie; 2003
• University of Illinois Extension: What Is An Annual
• Texas A&M: What Is An Annual, Biennial, Perennial
• NC State University: Types of Annual Flowers