Once you find containers for your house, set them in the location you have chosen. Check to make sure there are adequate drainage holes, which are about the size of a dime or a penny. Small containers usually need only one hole, but some large containers need three or four. Use a drill to make new holes or expand existing ones, if necessary. If your planters are located on flat surfaces such as concrete and don't drain well, elevate them by setting them on bricks. Many garden shops sell "pot feet" that sit on the outer edge of the planter's base, raising it an inch or two above the ground to allow for better drainage.
Select a quality potting soil. Many of the premium mixes cost more, but some contain timed-release fertilizer and water-retaining polymers, which cut down on maintenance. Avoid buying cheap soils that don't list their contents on the bag. Fill planters with soil, and water thoroughly. Many of the mixes are hard to get wet, so use your hand to stir the soil, mixing it with the water. If the soil settles, add more. The final soil level should be about an inch below the top of the pot.
Before you actually purchase plants, consider the amount of time you're willing to spend tending them. Many evergreens, such as juniper, boxwood, and yaupon holly, are classic low-maintenance plants. Small trees and shrubs can be used effectively in large containers to add height to the landscape. Obelisks or small trellises may also be placed in planters to allow evergreen vines to climb.
Decide whether your containers will house a temporary or permanent planting. Annuals and perennials are short-term seasonal plantings. They usually require a little more work but reward you with variety and lots of color. If you mix several types of plants in one container, make sure they share the same growing requirements, such as light and water.
Measure the width and depth of your container if you plan to use a small tree or shrub. Make sure the plant you purchase will fit into the container and still have a little room to grow. Don't stuff an oversize plant into a small planter. It won't have enough space and will be hard to keep watered.
When selecting flower colors, there are a few rules to keep in mind. Use dark-colored blooms in front of a light-colored house and light-colored blooms in front of a dark house. Don't place too many colors in one pot. If you have more than one pot, repeat the same color in each one for continuity.
"Choosing and Using Containers" is from Southern Living 2004 Garden Guide.