It’s always a shame that just when the window boxes have reached their peak of fullness and color, autumn sneaks in and nips at the foliage and flowers, signaling it’s time to clean them out. Or is it? This season, try extending the life of your window boxes, so you can appreciate their beauty year-round, each time you glance out your winter windows.
To spruce up your boxes, start by removing what looks old and tired: the geranium leaves are beginning to yellow, the verbena is way past its prime, and the dianthus isn’t flowering anymore. But the ageratum seems to be perking up now that the heat of summer has passed, and the ivy and vinca are holding their own. You can fill in gaps with cool season flowers such as mums and pansies and probably get another three weeks of flowering out of those boxes.
When freezing temperatures arrive, it’s time for flowering brassicas, such as kale and cabbage, with their colorful, curious foliage. Plant them directly into the boxes and they will last all winter long through the harshest of weather. As you plant, tuck daffodil and tulip bulbs under the flowering kale to guarantee an early spring show. You can mix in cut sprigs of crabapples, viburnums, winterberry, or any other shrub or tree with clusters of colorful berries and strong branches. Just stick the branches into the soil in the boxes, and your only problem will be the birds and wildlife competing for the berries! Tangled grapevines and bittersweet, with its orange seed coats and red berries, quickly go from noxious weeds growing in the wild to precious commodities in autumn and winter window boxes.
Evergreen branches from spruce, balsam, and fir will retain their color throughout the winter months as long as the temperature is low. Stick their ends into the soil just before the soil freezes, arranging them en masse. For the holidays, string little white lights through the boughs and tie on weatherproof velvet bows. Discard the branches once the temperatures start to warm, but don’t worry, your window boxes won’t be bare for long. The tulip and daffodil bulbs you carefully tucked in for the winter will soon be coming to life, and the cycle will begin anew.