As the fall leaves begin to drop and the cool temperatures begin to rise, winter-loving evergreens and flowers emerge to brighten up the garden. Winter plants are most often hardy and frost-tolerant varieties that require well-drained soil to thrive. Grown in many varieties, each winter plant brings to the landscape its own distinct color, size and shape to provide a much-needed respite from winter's dull, dreary presence. Many winter plants are suitable for a window box.
Winter perennial blooms are hardy flowers that grow well in a winter window box. Frost-tolerant, hellebores are striking perennial flowers that grow 1 to 3 feet tall and wide and enjoy the cool climate of winter. The blooms are pink, yellow, white, lavender and green. The bright green leaves compliment the flowers and have a leather-like texture. Hellebore flowers can be divided after their blooming season to grow in other areas of the garden.
Alongside the hellebore, plant the winter-loving October skies aster flower. They produce an abundance of mounding blue flowers that provide color during the cool winter months. Draping over the window box, October skies asters are striking.
Evergreen Ground Covers
Evergreen ground covers provide color and texture to the window box all winter long. These plants retain their needles and color throughout the winter. October Daphne is a hardy, winter-blooming ground cover. It has a low, mounding form that grows 6 to 10 inches tall and 12 inches wide, and is ideal for draping over a winter window box. The arching, fleshy stems are blue and green, and edged with a deep pink line that surrounds each leaf. Drought-tolerant, October Daphne has pink flowers that grow in 8-inch stems to light up the winter box with color. October Daphne prefers full sun and well-drained soil, so make sure the window box receives adequate sunlight.
Flanking the winter window box, add a clump or two of lamb's ear. Lamb's ear, another evergreen ground cover, grows in upright clumps to provide a burst of gray green color to the window box. The velvety lamb ear-shaped leaves grow in small tufts up to 18 inches tall and provide an aromatic scent to the window box.
Annual flowers die back after their one round of blooming, but pack a bright landscape punch when planted among a winter window box. The pansy is a hardy, long-lasting annual flower. Pansy flowers grow in small mounds in a rainbow of colors, each with its own size and shape. Small pansy flowers, also called violas, are a miniature version of the regular-sized pansy and ideal tucked along the front of the window box to help fill in the small, hard-to-reach areas.
Compliment the pansy with an ornamental kale or cabbage. Both are annual plants that grow in a rosette shape that ranges from 1 to 3 feet tall and wide. The bright colors include, pink, purple, white and green, which intensify as the temperatures drop.