Flower boxes, whether mounted below a windowsill or affixed to a deck railing, traditionally showcase bright, seasonal flowering annuals. However, these containers can serve a more dynamic and long-lasting decorative purpose. Shifting the focus away from traditional flowering plants allows these planters to become adaptable elements of a home’s exterior. This approach often leads to lower maintenance requirements and offers year-round visual appeal.
Edible and Aromatic Alternatives
Transforming a flower box into a miniature edible garden is a practical choice, especially for those with limited space or a desire for ingredients close to the kitchen. Shallow-rooted herbs like chives, parsley, and cilantro are excellent candidates, thriving in containers six to eight inches deep. Cilantro, which tends to “bolt” or go to seed quickly in the heat, benefits from the slightly cooler microclimate often created by planting boxes near a structure. Mediterranean herbs like thyme and oregano prefer well-draining soil and a sunny location. These perennial herbs are drought-tolerant and can be paired successfully due to their similar low-moisture needs.
Mint, conversely, requires a deeper container (ideally 10 to 12 inches) and should often be planted alone, as its vigorous root system can quickly overwhelm other plants. Beyond herbs, various compact vegetables are well-suited for container life. Dwarf varieties of crops like ‘Tom Thumb’ lettuce and radishes only need a shallow root run and can be harvested quickly. For a box deeper than 10 inches, consider planting bush-type dwarf tomatoes or small pepper varieties, which are bred to remain compact while still producing a yield. Grouping plants with matching requirements, such as pairing sun-loving rosemary with thyme, is important for success in the restricted environment of a planter box.
High-Impact Foliage and Texture
Selecting plants primarily for their foliage, structure, and texture achieves a truly year-round display. Colorful leaf varieties, such as coleus and sweet potato vine (Ipomoea batatas), provide saturated color from chartreuse greens and deep purples to variegated pinks and reds. This leaf color remains consistent throughout the growing season, eliminating the need for deadheading. Integrating trailing plants softens the hard edges of the box and creates a cascading effect. Creeping jenny (Lysimachia nummularia) offers bright, coin-shaped leaves that spill over the side, while ivy provides a classic, dense screen of green that often maintains its appearance through milder winters.
For a more architectural look, small, slow-growing evergreens, such as dwarf cypress or boxwood, can be placed as a central “thriller” element, providing shape and height that endures all year. Succulents and sedums are another category of foliage plants that deliver high-impact texture with minimal care. Their fleshy leaves are adapted to store water, making them highly drought-tolerant and suitable for hot, sunny exposures. Pairing varied foliage types—such as ornamental grass with hosta or ornamental kale—ensures visual interest is maintained through contrast in leaf size and form.
Non-Plant Seasonal Displays
For times when planting is impractical, such as during the peak of winter or late fall, the flower box can transition into a purely decorative element using non-living materials. This approach offers a simple way to change the home’s exterior aesthetic quickly and without any horticultural maintenance. A fall display can incorporate natural textures like decorative gourds, small pumpkins, and bundles of dried corn stalks or birch logs.
As the weather cools, the focus can shift to robust winter elements, such as cut evergreen boughs from pine, cedar, or fir trees. These cuttings, combined with materials like pinecones, holly branches with berries, or red dogwood branches, offer color and texture that withstand freezing temperatures. To anchor these items securely, the box can be filled with dry sand, gravel, or floral foam, which provides a dense base without the mess or weight of frozen soil.
This non-plant strategy allows for the integration of festive, artificial elements like battery-operated string lights, colorful glass ornaments, or artificial berry sprays. By treating the container as an outdoor decorative vessel, seasonal themes can be swapped out effortlessly, ensuring the window box remains an active and attractive focal point year-round.