By Bodie V. Pennisi
University of Georgia
Because you're working within a limited space, stick to some basic design principles:
Focus: Draw the eye toward the center of the garden and let the other plants complement and "flow" around this center.
Form: Each plant in the design has a growth habit, or form. Some have strong upright habits. Others are sprawling, while others grow as a mound.
Texture: Some plants have linear leaves, like grasses, dracaena spike or cordyline. Others have rounded leaves, like ornamental potatoes and geraniums. A good design will use a variety of textures to make a feast for the eye.
Proportion: For a balanced look, don't let the plants be more than two-thirds of the overall height of the container garden.
For shallow or small containers, choose plants that won't get too large or plants with small foliage, or both. For large or tall containers, choose plants with medium to tall mature size or those with large leaves, or both.
Mix plants with at least three foliage textures to make a container garden interesting. Coleus cultivars come in many foliage colors, shapes and sizes. They can help "echo" the color of flowers.
Vary the shape of the flowers to add interest. For example, try petunias and verbena. Use bicolor flowers, too.
PositionsFor the best effect, be familiar with the various plant positions in the container garden.
The role of the center, for instance, is to fill in the crown of the container. Use plants with compact, upright growth such as salvia, grasses, Dracaena spike, coleuses, Persian shield, Alocasia, Colocasia and some perennials.
Plants in corners grow well over containers' edges, where they have the most elbow room. Good corner plants include petunias, million bells (Calibrachoa), torenias, scaevolas, plectranthus, helichrysums, fuchsias, ivy geraniums and angel wing begonias.
Use plants on the edges to drape over the side, softening the look of the container and filling out the spaces between corners. Good plants for edges include ivy, bacopas, verbenas, vinca vines, portulacas, ivy geraniums, plectranthus and sweet potato vines.
Finally, filler plants have compact, upright growth and round out the top of the container. Good examples are argyranthemums, geraniums, coleuses, iresines, cupheas, strawflowers (Bracteantha), Dusty Miller and Heliotrope.
TipsSoils for containers must be well-drained with good aeration and able to hold enough water to keep plants growing well. If you have plants that need a lot of water and use moss or coco fiber baskets or any container that allows high evaporation, consider adding a water-retaining agent to the soil mix.
It's best to either use a soilless mix with slow-release fertilizer already in it or apply a slow-release product at planting. Don't use granular fertilizer or weed-and-feed products.
The basic rule for a successful container garden is that all plants in one container should have similar water, light and fertilizer requirements.
For places with 4 to 12 hours of sun a day, select plants for full sun to partial shade. For those that get 2 to 4 hours of sun daily, select plants for partial or full shade.
For the best results, select plants that perform best in the season ahead: cool-loving plants for spring and fall and heat-loving plants for summer. Most Marguerite daisies, lobelias and nemesias, for instance, look great in the spring but decline in Georgia summers.
Don't put your container garden in a windy site. Plants in windy, hot places may require watering every few hours just to survive, especially if the plants are large or the container small.
Whether you're a gardening expert or not, try planting a container garden. You'll be rewarded.
(Bodie Pennisi is a Cooperative Extension floriculture specialist with the University of Georgia College of Agricultural and Environmental Sciences.)