Winter Window Box Treatments
Gardeners in cold temperatures have to forgo planting their window boxes in winter, but in mild, Mediterranean-style climates, you can keep them growing and booming year-round. Use plants that can take frost and also an occasional hard freeze, and also take more actions to protect the roots from freezing temperatures. As you won’t find because many plants for winter window boxes as for other seasons, you’ll find a broad range of color to keep the box interesting.
The very first step in making a winter window box is setting up a box which can provide additional protection for the roots. Roots that grow within an above-ground planter are subjected to harsher conditions than those growing in the ground. One way to protect your plant’s roots is to plug the plants, pot and all, into a window box filled with bark chips. Use plants which are growing in pots at least 4 inches in diameter.
A few low-growing evergreen shrubs with colorful foliage form an outstanding background for a bay window box. Wintergreen (Gaultheria procumbens) is a narrow-leaved evergreen with a brand new, winter vacation scent. The branches of the tree stretch a foot or more beyond the edges of the window box, giving it a multi-dimensional impact. Wintercreeper euonymus (Euonymus fortunei) can be erect, mounding, or trailing. “Emerald and Gold” is an erect cultivar includes gold-tinted leaves which turn pinkish red in cold weather. Miniature conifers which are sold for the winter vacations as mini Christmas trees make the box appear to be a very small landscape.
Pansies (Viola spp.) and polyanthus (Primula spp.) May bloom throughout winter in mild climates, and between them, they blossom in virtually every color in the rainbow. Sweet peas (Lathyrus odoratus) and pinks (Dianthus chinensis) also blossom in winter window boxes, but they might not last all year. Because they are grown in individual pots, it’s easy to switch them out if they start to appear bedraggled. It’s possible to grow sweet peas in a mound, or provide them to climb and allow them to soar. Deadhead all of those flowering plants frequently to keep them blooming.
Plants that tumble over the sides of a window box add an excess dimension to your groupings, but trailing plants for winter boxes are limited. Creeping lantana (Lantana montevidensis) includes foliage that lasts all winter, and it produces winter blossoms in frost-free places. Trailing forms of euonymus (Euonymus fortunei) have stems that are less than 1 foot long and often variegated.