Window boxes were supposedly invented in Venice to contain aromatic plants that repelled mosquitoes (and probably because garden space was so minimal in Venice). Hanging plants like nasturtium and ivy geranium are traditional window box plants because they do not obscure scenery or sunlight. Scented geraniums are also popular because they are be so strongly aromatic.
Scented geraniums are of the Pelargoniuim genus, so are related to ivy and common geraniums, but are a mix of a few different specie and hybrids. Their foliage can smell like rose, lemon, orange, apple, strawberry, ginger, mint or other herbs or spices. Specialty geranium growers may have nearly a hundred varieties to choose from, which is less than half of the known varieties.
Not many scented geraniums bloom with impressively colorful flowers. However, many have interestingly textured, colorful and lobed foliage that might be velvety or even raspy. The more compact varieties stay less than a foot tall, and spread laterally very slowly. Others have longer but limber stems that lay low as they spread like sloppy ground cover. A few stand upright as tall as five feet.