Wildflower is published quarterly by the Wildflower Center. Its content is national in scope with articles about the conservation and use of native plants as well as news from the Wildflower Center. A subscription is provided to Wildflower Center members as a benefit of membership.
Enchanted Evenings by Randall Frost, Ph.D. - Summer 2004
A new world of plant life emerges in the moonlight, dominated by white, richly fragrant flowers and dependent upon specific pollinators. Night gardeners - especially in warmer climates - can enjoy coming home from work with time left to appreciate the fruits of their labor.
Gardening expert and horticulturist Scott Ogden, author of "The Moonlit Garden," says nocturnal gardens can be traced throughout time. "The ancient Persians grew jasmine in their night gardens. In China, moon gardens were about nocturnal experiences; the Chinese made use of plants that are fragrant at night like the sweet olive (Osmanthus spp.)," Ogden notes. "Many of the pre-Columbian gardens involved night-blooming plants as well. In Maya territory, one of the sacred trees - now sold as a tropical houseplant - has a nocturnal flower. And the sacred tree of the Aztecs is a cousin of the magnolias with a nocturnal bloom."
Ogden, who makes his home in Austin, Texas, says, "For those of us who live in the Southwest, where it is blistering-hot or unpleasant during the day, night is a time when we can enjoy being outside." He adds, "It is a natural time for us to interact with nature."
The Night Life
Although most of the world's night-blooming plants tend to be found in the warmer latitudes, night gardens are not just for residents of the southernmost states. Night-blooming plants can be grown and enjoyed throughout most of North America. Plants that bloom nocturnally are fairly easy to identify, even if you haven't actually seen them in bloom.
According to Professor Larry Mellichamp, a biologist at the University of North Carolina in Charlotte, "They are usually white to yellowish or light-colored and very fragrant." Mellichamp adds, "I always assume until proven otherwise that naturally white flowers of any kind are night bloomers, and it is best to check for the strongest fragrance at night. Pollinators must be attracted to the flowers primarily by scent, not particularly by color."
Mellichamp also points out that night-blooming flowers tend to have competitive advantages over those that bloom during the day. The lack of heat in the evening means the flowers do not dry out or lose nectar through evaporation - a definite advantage in the desert. In general, Mellichamp says that cool climates afford night-blooming plants few advantages and provides them with little ability to withstand predators. But in warm regions, "night flowers have fewer pollinators 'stealing' their pollen and nectar. Night flowers have fewer but more loyal pollinators - a very efficient system. The flowers are definitely more specialized for their particular pollinators."Scott Ogden notes that in the warm summer regions of North America, there tends to be a shift in the summer to night-time pollination. "All through the subtropical Southeast, Midwest, and Southwest - places where you have relatively warm temperatures at night - there will be a lot of night-flying pollinators," he says. "Most of them are insects such as hawkmoths, but you have bats in part of the Southwest as well. There are also a lot of crepuscular animals such as hummingbirds that are active at dusk or dawn and which may visit the same plants that attract the bats or moths."