Window boxes are ideal solutions for gardeners with small spaces, or people who don't have a lot of time to spend in the garden. They beautify porches, balconies and windowsills and they don't need a lot of care to be successful. When planning your window box, make sure you choose plants suited to the available light requirements and use light, well-drained soil.
A window box doesn't have to be in a box. You can put a few small pots in a basket, or use old cups, bowls or cooking pots. Even an old shoe or milk carton can hold annual flowers. The West Virginia University Extension Service points out that any container will do as long as it has adequate drainage and won't dry out too quickly. The container also should be at least 6 inches deep to accommodate a plant's roots.
Annual herbs like basil, parsley, dill and cilantro grow easily in window boxes as do perennial herbs like thyme and marjoram. These plants are generally compact and bushy, and they can handle being closely planted with other herbs and flowers. Place the window box near the kitchen, and you can snip off herbs whenever you need them.
Many vegetables grow quite happily in window box containers. You can fill a box with mesclun salad greens for fresh salads and colorful, varied foliage. Chanteray carrots are a baby carrot variety that grow well in containers, as do dwarf cherry tomato varieties. Edible or flowering kale add color to a window box garden until the first hard frost, and nasturtium produce tasty eye-catching flowers for several months with regular harvesting.
Annuals and Perennials
Mixing annual flowers and perennial plants in a container gives your window box a nice accent all year around, and you can change the design with new annuals each year. To make the most of colors, consider mixing a variegated trailing ivy plant with shade-loving flowers like impatiens or begonias, or grow some tulips or daffodils with sage or lavender.
Perfume you home naturally with gentle scents wafting in from your window boxes. The foliage on lavender and rosemary smell wonderful in the sun's heat. A trailing night-blooming jasmine sends out a sweet heady aroma as the sun starts to set, and can be trained to climb or spill over the edge of the box. Some people don't like the strong smell of marigold, but they discourage flies from coming in an open window. Phlox, sweet alyssum, stock and nicotiana are all fragrant flowers that do well in planters.
Mix & Match
It's hard to make a mistake when designing a window box, so long as the plants inside have similar watering and light requirements. Don't be afraid to pack the boxes as tightly as you can with a riot of colors and textures. Tall spiky flowers and grasses look nice with bushier plants underneath, and a window box looks even more bountiful with ivy, petunias or nasturtium pouring over the sides. Or, you can create more formal-looking window boxes by mixing only one or two flower colors and foliage types.