Window boxes are brilliant pockets of living color that turn facades into gardens.
By Nancy J. Ondra | Photographs by Rob Cardillo
With planters in the window, you can easily match outdoor home decor to the seasons. These boxes overflow with the vibrant colors and lush foliage of tropicals that thrive in our region's hot and humid summers.
Window boxes do for the outside what curtains do inside: They brighten an otherwise plain wall with color and texture, adding a dramatic finishing touch to your home. On city blocks and anywhere outdoor growing space is limited, window boxes can be the primary planting spots for gardeners who want to surround themselves and others with lush flowers and foliage. The boxes can host a year-round display of nature’s beauty for the enjoyment of residents, neighbors, and passersby.
Each season, you can find many exceptional examples around Philadelphia, and last summer, we captured a handful of them at their peak. On the following pages, you’ll see a variety of imaginative window boxes on homes around Delancey Street. The designers of these planters share their insights on the best varieties and combinations, and they offer tips that you can use to create your own wherever you live.
Consider the container
Window boxes are essentially permanent features, so high-quality materials are worth the investment. Wood is a traditional choice and easy to paint to match the color of your shutters or trim, as PHS member Melissa Gordon Pinheiro did with the wooden boxes shown here. Some designers avoid wood because of its tendency to rot, but Pinheiro has enjoyed her custom-made boxes for nearly seven years now, thanks to plastic liners that keep the moist growing medium away from the container walls.
When the boxes are in proportion to your windows and complement the style of your home, they can be pleasing even when the plants are not at their peak. Pinheiro depends on small boxwoods (Buxus sempervirens) for ongoing interest but changes the companions from year to year. This planting, for instance, included a sweet potato vine (Ipomoea batatas) called ‘Blackie’; rex begonias (Begonia Rex Cultorum Group); and caladiums, which continue to look beautiful even after the summer’s tuberous begonias are done blooming.
The larger your container is, the more planting options you have. The length depends on the size of your window, of course, but allowing for an ample depth and width is critical. “Anything less than 6 inches by 6 inches is too hard to work with,” advises designer Gary R. Keim. Large boxes can get very heavy, though, so it’s important to make sure they are securely attached to your home before you fill them with growing mix and plants.
Including a combination of upright, bushy, and cascading forms creates the effect of an entire garden, even where space is at a premium. For a touch of artistry, pair classic container plants with lesser-known hardy and tender specimens, as Keim did here by mixing impatiens, sweet potato vine, creeping Jenny (Lysimachia nummularia), and wishbone flower (Torenia fournieri) with Scotch broom (Cytisus scoparius).
Mix it up
Why limit yourself to just one or two different plants in your window box? Including a wider variety lets you try out interesting combinations of colors and textures. It also extends the longevity of your design. If one plant is slow to get started or fizzles out early, the others spread out to fill the space.
Where you’d like to enjoy a bountiful window box display without blocking your view stick with relatively low, bushy plants, but mix things up with different leaf shapes and sizes, as Keim did with this arrangement of bold ‘Pink Beauty’ caladium, lacy American aborvitae (Thuja occidentalis), broad-leaved heuchera, and a dainty pink begonia. It also includes several selections of coleus: a plant group Keim turns to often for its range of colors and textures, as well as its adaptability to different levels of sunlight and shade.
Look beyond the obvious
Instead of trying to get a decent show from sun-worshipping flowering favorites in shade, take a tip from professional window box designer Beatrice Ryan, founder and owner of Philly Facades. Try expanding your plant palette to include choices typically treasured as indoor foliage favorites, such as spider plant (Chlorophytum comosum), sansevierias, philodendrons, and crotons.
Summer interest in this particular tropical-themed box comes from ‘Black Magic’, a dramatic elephant ears (Colocasia esculenta) variety; elegantly trailing devil’s ivy (Epipremnum aureum); and a complement of bushy flowering and foliage fillers, including pink-flowered impatiens, a polka dot plant (Hypoestes phyllostachya) called ‘Splash Select Pink’, and several colorful cultivars of coleus.
Create a new view
In the garden, tall plants are invaluable for blocking an ugly view and providing both a welcome sense of privacy and much-needed shade. They can serve the same function in a window box, which makes them particularly useful if you’d like to screen out scorching sun or a less-than-pleasing scene and have beautiful blooms and lovely leaves to look at instead.
To keep the box from looking top-heavy, balance the tall plants with one or more equally vigorous trailing partners. This collection skillfully contrasts upright ‘Pretoria’ canna with a cascading purple-leaved sweet potato vine and other bushy or trailing companions, including conical dwarf Alberta spruce (Picea glauca ‘Conica’), zonal geranium (Pelargonium × hortorum), pink verbenas, purple petunias, and licorice plant (Helichrysum petiolare).
Look to the leaves, but don’t forget flowers
There are many good reasons for filling your window boxes with fancy foliage. Leaves last much longer than flowers, supplying dependable color and eye-catching forms throughout the growing season. Foliage needs minimal grooming too: just the occasional trim to remove any leaves that are damaged or discolored. That’s a significant plus in many situations, since it can be challenging to reach window boxes for maintenance, especially on upper-story installations.
That doesn’t mean you need to go without flowers altogether. Those that bloom on trailing stems, such as petunias and verbenas, show off especially well when cascading over the edge of a container. The raised positioning of a window box is also ideal for showing off long-blooming plants that have nodding blossoms, such as Dragon Wing Red begonia.
Think beyond the box
Dramatic window box displays do more than beautify your home: They enhance your entire neighborhood. If space allows, tie the setting together with ground-level planters filled with more foliage and flowers. Using some of the same plants in the box and the pots—as designer Paul Kawoczka, co-owner of Enliven Planters, did here with purple- and chartreuse-leaved sweet potato vines—links the two features visually. Coleus, petunias, and a variety of other annuals and tropicals complete this colorful streetside spectacle.
Creating photo-worthy window boxes like these is the result of smart plant selection. “Often homeowners opt for instant gratification and buy plants already in full bloom,” Kawoczka says. “Then they are disappointed when the plants underperform, stop blooming, or die within a few weeks.” Instead, you can take advantage of the flexibility that window boxes offer by adapting them to the changes in the seasons. Plant tropicals and other heat-loving selections that thrive through our region’s sweltering summers.
Nancy J. Ondra, who lives in Bucks County, Pennsylvania, is an accomplished gardener and a prolific writer whose latest books include The Perennial Matchmaker and Container Theme Gardens. She blogs at hayefield.com.