The best window box is the one you can't see. Whatever you planted in there should be so happy that it cascades down the wall to spill onto the sidewalk, threatening to trip passersby. Here's how to get the look:

Above: Coleus, sweet potato vine, and caladium: They like a little shade, which makes them the perfect combination to plant beneath a balcony or eave. Water them every day. Image via Stately.

Above: Just try to stop sweet potato vine after it gets going. The chartreuse shock of Ipomoea 'Bright Ideas Lime' complements purple and red shades; consider pairing it with Ipomoea 'Bright Ideas Rust' (both are $10.95 per plant, from White Flower Farm). Image via Katie's Flowers.

Above: Coleus is a tropical plant; its range of colors is exuberant. For a compact variety, we prefer the deep burgundy of Coleus 'Garnet Robe' (Above), with leaves edged in chartreuse; it's $8.95 per plant at White Flower Farm. But if you were leaning more toward magenta, we totally understand; Coleus 'Stained Glassworks' is a trailing variety to consider ($9.95 per plant at White Flower Farm).

Above: The intense pink and green shades of Caladium 'Carolyn Wharton' show best in shade; this plant needs to be fertilized regularly. It's $10.95 apiece from White Flower Farm.

Above: A simple Pine Window Box is unfinished; paint it to match your trim. Prices range from $36 to $54 at Jamali, depending on length.

Above: No need to paint these. Teak Windowboxes come in a variety of lengths and depths; prices range from $55.95 to $137 from Gardeners.

Above: Teak Windowbox Brackets come in three sizes, to accommodate window boxes with depths of up to 12 inches; prices range from $14.95 to $19.95 per pair from Gardeners.