Until recently, growing annual flowers, either outdoors or with a hydroponics system, meant having just a few choices--among them geraniums, impatiens, marigolds and red salvia.

Today that's changed as a number of other options are available to spice up a garden that would otherwise be perennial in nature.

Technically speaking, an annual is one that has its entire growing (from seed, flowers and production of seed) in a single growing season. But an even wider range of plants are treated as annuals, including impatiens, heliotrope and tuberous begonias that are really "half-hardy" perennials that can't survive even a light frost.

Some annuals, pansies and ornamental cabbage included, can better withstand freezing temperatures.

Annuals have diversity and versatility and allow the hydroponics or traditional gardener to create exciting combinations of color, form and texture, the colors ranging from the bright midsummer zinnias and Mexican sunflowers, to the subtler pastel shades of stock or lavatera.

Choices can be made on characteristics other than flower color.

Height is one consideration (there are tall, medium, short or climbing varieties) and the sensitivity to light is another (some prefer either full sun or partial shade).

Fragrance (stock, mignonette, nicotiana come to mind) or attractive foliage (caladium, coleus, dusty miller) are other factors to consider.

To some extent, determining whether a plant is an annual or perennial is a matter of whether the plant will survive the winter in the gardener's area.

Many gardeners simply treat tender perennials plants as annuals, enjoying them for the one season before they die of the cold. Others move them indoors and treat them as houseplants, taking cuttings and starting new plants or digging up and storing roots or bulblike structures indoors for replanting the following year.

Perennials commonly grown as annuals include the more tender flowering sages. Geraniums and scented geraniums. Petunias, coleus, and sweet-alyssum can be overwintered in pots and replanted the following year.

Gardeners who have a sunspace or attached greenhouse with plenty of winter sunlight might try growing some of the interesting "annuals" that are actually perennial shrubs and trees. As an example, given year-round protection, fuschias grow rapidly, reach anywhere from 18 inches to 12 feet or more, and produce their beautiful pendulous blossoms in shades of red, purple, and white nearly all winter long.

Some people begin their plants from seed, either hydroponically or otherwise, a big savings over buying annuals in flats from a nursery or garden center.

Another reason is that garden centers don't always carry the full selection of worthy garden annuals. It might be difficult to find old-fashioned annuals, such as love-lies-bleeding (Amaranthus caudatus), four o'clocks (Mirabilis jalapa), or lavatera (Lavatera trimestris).

Economics may be one reason, there not being enough demand for the variety of species.

That, coupled with the way of growing and buying is also a factor. Garden centers typically sell six-packs of plants that are already in bloom and some annuals won't start blooming in nursery six-packs, either because they are too tall, don't like to be transplanted, or won't flower until they have been in the ground for a couple of weeks. Experimenting with the whole palette of annuals will ultimately involve growing some of your own plants from seed.

While many annuals are easy to seed directly into garden soil, others are best started indoors under lights in late winter or early spring. And some annuals are so good at flowering and setting seeds that they will self-sow readily under the right conditions and produce brand-new plants the following year.

Hardy annuals, which include bachelor's-buttons, calendula, spider flower (Cleome hasslerana), pinks (Dianthus spp.), larkspur, linaria, Shirley poppies (Papaver rhoeas), nigella (love-in-a-mist), scabiosa (pincushion flower), snapdragons, lavatera, annual baby's-breath (Gypsophila elegans), heliotrope, stocks and sweet peas, can be sometimes direct-sown in the garden as early in the spring as the soil can be worked.

Half-hardy annuals, including statice, nicotiana, painted-tongue (Salpiglossis sinuata), China aster (Callistephus chinensis), and various types of salvias and chrysanthemums, can be direct-sown outdoors after the threat of hard frost (temperatures below 25 degrees F) is past.

Tender annuals, including marigolds, morning glories, zinnias, sunflowers and tithonia (Mexican sunflower), cosmos, amaranth, ageratum, celosia and gomphrena (globe amaranth), can be sown directly in the garden only after all danger of frost is past. For an earlier start, sow seed indoors four to six weeks before the last spring frost date for your area.

When taking cuttings from annuals, the idea being to pot them up for winter bloom indoors or hold them over to the following spring, the following steps will help ensure success.

1. Clip off any flowers or flower buds on the plant in order to focus the plant's energy into developing new roots on the stem cutting.

2. Select healthy stem cuttings (preferably healthy growing tips or side shoots) that are 2 to 6 inches long, stripping off any bottom leaves where the stem will be inserted in the rooting medium (either potting soil or water). Dip the cut end of the stem into a rooting hormone powder to encourage rapid root growth.

3. Insert the cutting in potting soil (not a soilless seedstarting mix) and water the container. Cover the flat or pot with a clear plastic bag to create a moist, humid atmosphere. Don't let the plant leaves touch the side of the bag because this will cause rot.

4. New roots should develop in one to three weeks. To test, gently tug on the cutting. Pot up the new plants in 4- to 6-inch containers and keep out of direct sunlight for three days. After this time, place the plants in a sunny location.

5. Rooting plants such as begonias, coleus or geraniums can be done by placing the stem cuttings in a glass of water to develop roots, changing the water every few days until plants develop roots, and adding a little soil to the jar after new roots appear. Plant rooted cuttings in 4- to 6-inch containers filled with potting soil.

6. Once the new plant is well established, pinch off the stem tip to encourage fuller growth and more abundant flowers.