Why Do Moonflowers Bloom at Night?

The moonflower is renowned as a treat for those who stroll through their gardens in the evening. Peeking open at night, almost as if they were seeking a rendezvous with the moon, the flower's scent draws a nocturnal moth to pollinate the flower.

The moonflower, so called because it blooms only at night -- flowering in the late afternoon and closing by morning -- produces only white flowers and will be viewed only by those who venture outside in the evening hours. That is because the flower is pollinated by night-flying moths and blooms in the dark -- while emitting a special scent -- to draw those moths, reports the Texas Cooperative Extension service.

On a warm, summer evening, moonflowers will open in a matter of minutes. They’ve evolved their white coloring to better attract the moth for the pollination necessary to perpetuate the species. A plant that grows quickly from seed, the leaves of the moonflower often extend 6 inches across, as do the solitary white blooms marked with a five-pointed star of a slightly different shade of white.

The moonflower (Ipomoea alba), is related to the morning glory and produces a long, slender vine that may grow a dozen feet or more. It typically climbs fences, drops over shrubs, and can be trained to advance up a string.

The University of Arkansas indicates the plant is believed to have originated in Central America, but now grows wild in tropical locales and is cultivated by gardeners elsewhere as an annual or perennial.

Seed is the most common way of growing the plant. The seeds should be scraped with a knife or rubbed by sandpaper to puncture the hard coating, and thus improve germination.

The soil temperature should be above 65 degrees Fahrenheit before you plant the seeds. Plant moonflower seeds in a site that receives full sun; it requires six hours of sunlight daily.