Moonflowers are night blooming vines in the morning glory family. Their name is a reference to the fact that they bloom at night, rather than a suggestion that they originate on the moon. These annuals are very popular in moonlight gardens, gardens specifically designed to be viewed at night, and they can be used in a regular garden as well. Many gardeners in the American South include moonflowers in their landscaping, as these vines thrive in the warm, humid environment of the South.
Generally, moonflowers should grow well in USDA zones eight through 11, although some people have success growing them in even cooler regions. Moonflowers are typically started from seed, indoors in areas where late spring frosts occur, and outdoors in warmer regions. Because moonflower seeds are very hard, many gardeners recommend soaking or nicking the seeds before planting to promote germination. Indoor starts should be grown in peat pots which can be buried directly in the ground during planting, as the roots of the seedlings are fragile.
These vines like a spot which gets at least six hours of sunlight a day, and they prefer well-drained, loamy soil, with intermittent waterings. The vines grow quickly, typically latching onto anything within reach and developing dark green heart-shaped leaves and delicate white flower buds. In the summer, the buds will open up at night, releasing a rich fragrance and flashing their creamy-white interiors, which stay open until sunrise.
Night-bloomers have evolved to take advantage of moths and other insects which are active at night. The luminous white of the flowers is designed to be eye-catching, while the aroma is attractive to animals that cannot see the flowers. The flowers are also quite large, to increase visibility, and in addition to coming in basic white, some cultivars are a delicate pink.
In most regions, moonflowers die back after the summer, when the weather starts to get cold, and they will reseed themselves unless they are deadheaded. The dead vines can be cleared away and composted or used as mulch. Many people allow the plants to reseed naturally, watching out for the young vines in the spring when the seeds germinate.
Some people consider moonflowers quite romantic, along with other night blooming flowers. They work especially well on trellises and along paths, where people will easily be able to see the bold white flowers at night. Moonflowers can also be grown near a window, so that people can enjoy the aroma from inside the house.