Window box planters can be ornamental as well as utilitarian. While most people picture window boxes full of flowers, there are edibles that are ornamental enough to be placed in a window box. Combining edibles with flowers can give your window box a double purpose.
Marigolds are native to the Americas. The first documented use was by the Aztecs, who claimed they had medicinal, magical and spiritual qualities. Marigolds have long been planted in vegetable gardens to repel insects. Dwarf marigolds grow from 6 to 14 inches in height and display a range of red, white, yellow, rust and bi-colored flowers. Marigolds like well-drained, loose soil rich in organic matter. They are heat tolerant and bloom in the hottest parts of the summer months.
Common oregano has a low-growing habit, which acts as a trailing habit in a window box. It blooms in white or pink flowers. Oregano's trailing form adds a touch of elegance to a window box arrangement. Common oregano will grow well in a variety of soils, but prefers loose, loamy soil.
If your window box is in a shady place, impatiens may well be your best choice. New Guinea impatiens can withstand more sunlight. Impatiens like a light, well-drained soil and like to be kept moist but not wet. Impatiens come in a range of colors from white to deep pink to lavender, and some have roselike triple flowers.
The trailing varieties of thyme come in green and variegated forms and grow very well with other plants. They like a rich, well-drained soil. Thyme tea has long been used as a calmative and tonic. Thyme benefits from frequent trimmings to keep it from getting spindly.
In the winter months, don't let your window box go naked. Pansies will withstand all but the coldest weather and will bloom well into the spring. Miniature viola varieties, such as Johnny Jump-Ups, are very popular for small window box plantings. Pansies require a rich, organic soil, but require no special care.
Globe basil is a low-growing, mounding basil with small leaves. It grows well in loamy, rich soil, but does not like hot, wet weather. Its tiny white flowers make it ornamental as well as edible. Grow globe basil in spring or early fall for best results.
Nasturtium is a trailing plant with edible flowers and leaves. The bold flower colors make a statement in any window box. Nasturtiums will grow in almost any soil and require hardly any care once established. Nasturtiums grow easily from seed and require full sun to bloom their best.