A flower garden can offer a romantic and fragrant feast for the senses, a renewable source for fresh bouquets, or simple color to brighten a patio or deck. The key is understanding what annuals and perennials are, knowing your planting seasons, and matching a plant's light and water requirements to what your garden offers.
 
  
Annuals 
 
1.   Remember that annuals are plants that grow, bloom, set seed and then die in one growing season, typically from spring to fall. In mild climates, some annuals grow and bloom through winter. Popular examples are petunias, marigolds and zinnias. Annuals generally produce maximum bang for the buck, but require seasonal replacement. 
 
2.   Choose cool-season annuals, such as pansies and Iceland poppies, for spring and fall displays (and winter in mild climates). 
 
3.   Select warm-season annuals, such as marigolds and impatiens, for flowering from late spring into fall. 
 
4.   Purchase seeds from catalogs or nursery racks, or buy seedlings sold in flats or small packs at nurseries. Starting from seed is less expensive but takes longer and is more labor intensive. Some annuals grow better when sown as seeds directly in the ground; others, such as begonias and petunias, take a discouragingly long time to grow from seed. Start your own seedlings at home for inexpensive and satisfying garden additions. Seedstarting kits are available at garden centers or from online dealers such as Gardener's Supply Company (gardeners.com). 
 
5.   Give a plant what it needs in terms of sun or shade. Most annuals prefer full sun. A few, such as impatiens and begonias, do well in shade. 
 
6.   Make sure you choose vigorous nursery seedlings. Examine them for healthy green leaves just coming out, and avoid seedlings with many yellow leaves. Select plants with mostly unopened flowers. Avoid any that are root-bound, with wads of brown roots coming out the bottom of the container. 
 
 

Perennials 
 
1.   Choose perennials if you want plants that live for several years or more. Some die back to the ground in winter and reappear in the spring. Some may remain green all year in mild climates. 
 
2.   Shop for perennials nearly year-round, generally in nursery containers or small pots. Starting perennials from seed takes time, and some seeds germinate only with special care, so this is an advanced project. During late fall, winter and early spring, many perennials, such as phlox, display no top growth, so it looks like you're buying a pot full of soil. 
 
3.   Try to plant most perennials in early spring or early fall. The earlier in the growing season, the smaller the container and the less expensive the plant will be. Perennials in 4-inch (10 cm) pots may look small, but they are actually easier to establish in the garden than larger plants. 
 
4.   Neighborhood nurseries and garden centers may offer limited variety. Check out specialty perennial dealers with mail-order or direct-mail catalogs; specialties include daylilies, geraniums and salvias. 
 
5.   Look for signs of vigor in a nursery plant: healthy green leaves just coming out, either right by the soil or on a branch. Avoid plants with yellow, limp leaves or those that are root-bound. 
 
6.   Buy perennials in bloom if you want to be sure of the color. 
 
 

 Easy-to-grow annuals include impatiens, marigolds, zinnias and sunflowers. 
 
 Save money by sowing nasturtium, sunflower, cosmos and California poppy seeds directly in the garden in spring. Make sure to keep them moist until they're established. 
 
 For a quick colorful effect in summer, look for sales on annuals potted in gallon-size containers. 
 
 Fail-safe perennials for sunny spots include yarrow, coneflower, daylily, and Shasta daisy. For shade, try bleeding heart, hellebore, hosta, and Japanese anemone. 
 
 You can increase your supply of perennials by dividing and transplanting existing plantings. The best timing depends on the type of plant, but generally you'd do this in fall and spring.