Symmetry in flower arrangement is important. Unless your home is an informal country cottage, the porch will look best with organized containers of flowers. For example, you may elect to place four 18-inch-high concrete containers of red petunias across your porch. Or you may want to hang just one basket of ivy from the porch ceiling on either side of the steps.
Use groupings of flowers in large containers. On a wraparound porch, for example, place a 36-inch round container every 8 feet adjacent to the house facade. Use a mix of flowers in each container, but create all containers to look basically alike. Begonias, marigolds, ferms and pansies all mixed together in specific patterns work well in these types of containers. Place chairs or tables between the containers if you desire.
Buy plant shelves for large Southern porches. Shelving units made of wood or metal with three or four shelves can fit on each side of the front door. An eclectic mix of flowers in coordinating pots might be interspersed with baskets of greenery. Make sure the shelves of flowers look appropriate from curbside so the porch doesn't look too informal.
Very formal arrangements are required for formal porches. A single topiary bush in a large ceramic container with a wreath on the door can look appropriate. A 4-foot-high square wooden container on each side of the door looks appealing with a small evergreen bush in each container.
Flowers on each porch step can look inviting. For example, if you have wide steps leading down from the porch to the front sidewalk, use matching pots of flowers on all steps. Place containers at the very edges of the steps and fill with cascading petunias. Hanging baskets of cascading petunias hung from the porch ceiling in strategic places can match the flowers on the steps.