On my patio there's a small collection of plants that may not win any beauty contests, but compensate for their lackluster foliage and odd-angled branches by another attribute- fragrance. All these plants happen to have white blossoms, and all smell more strongly once the sun sets.

This combination of light colored flowers and night fragrance is common in nature. A symbiotic relationship occurs between night flying creatures like bats and moths (who need to eat too!) and night blooming plants that need to be pollinated just like all the other flowers.

Pale colored flowers glow in the moonlight, making them easier to find in the dark by pollinators. A strong scent is another adaptation that night-blooming flowers have developed to help lead nocturnal animals to them. Some of these plants also are fragrant in the daytime, but the most powerfully scented, the night-blooming jasmine, has no fragrance at all between sunrise and sunset. Once it's dark, however, it can be smelled halfway down the block, or as I noticed recently, from inside a car with the doors and windows shut.

Because most of us aren't on the same schedule as the bats and moths, it is easy to forget what work goes on in the garden during the night shift. And sitting outside in the evening, as the fragrance of night-blooming jasmine and tuberose waft by, it's also easy to egotistically imagine that nature decided to create these amazing scents for no greater reason than to please us.