
After their invention in ancient Rome, window boxes became overly prevalent in Venice. They contained herbs and vegetables where space was limited within such urban areas. Their produce was close to kitchens, and more visually appealing than nearby buildings. Several window box herbs produced aromatic foliage for more than culinary application.
The popularity of window boxes preceded the availability of affordable window screens. Mosquitoes were a nuisance within the swampy ecosystems around Venice prior to that. Therefore, besides their obvious usages, window boxes also sustained aromatic foliage. Such foliage, which was mostly also culinary herbs, repelled some troublesome insects.
Just as flowers attract pollinators with fragrance, some foliage repels insects with aroma. Some aromatic foliage intends to repel other large consumers, such as rodents and deer. Any potential consumers know that flavor is likely as objectionable as associated aroma. Ironically, some flavors or aromas that are unappealing to them are appealing to people.
Culinary herbs are perfect examples. Their strongly flavorful and aromatic foliage is quite repellent to insects and wildlife. However, it is an asset both for culinary and horticultural application. Some such herbs have cultivars for either culinary or landscape application. Trailing rosemary is a groundcover that has slightly milder flavor than culinary rosemary.
Several cultivars of lavender are popular for home gardens even if not for home kitchens. Their aromatic foliage is as delightful as their foliar color and bloom. The foliar texture of fennel is as striking as its foliar aroma. Thyme is both an herb and an aromatic, although irregular, ground cover. Mint and oregano are a bit more casual, but likely more aromatic.
Some of the most popular aromatic foliage has no culinary application, though. Its aroma more than justifies its cultivation. Scented geraniums and sages are remarkably diverse. Although most are quite pretty, a few are simply very aromatic. Most aromatic foliage can not disperse its aroma like floral fragrances. It requires some sort of disturbance to do so. Warmth with humidity enhance typical foliar aroma.