Moonflowers are a relative of the morning glory and in fact, have a similar growing habit and appearance. Instead of opening in the morning, as their relative does, they open at night. They begin to open around six o'clock in the evening or later and stay open until the early morning hours. Although there are several species of that are called moonflower the real one's name is Ipomoea alba.
Moonflower blooms are a beautiful white. The blooms reach about 5 to 6 inches wide and are situated on a tube that is involved with the pollination of the flower making it look trumpet like. Inside the flower is a five point star that is in a different shade of white. The blooms grow on a vine that can grow 8 feet and upwards to 20 feet. The vine can be easily trained up a trellis or up twine that is hung vertically. The leaves are a green to bluish green and heart shaped about 6 inches across. The leaves grow dense and thick.
The moonflower is propagated by planting seed. Flowers that are spent will develop a hard dark brown to black seed if left on the vines. Once the flower falls off you can see the seed. These seeds can be planted in the fall before winter hits and they will germinate in the spring. They will also germinate and grow if planted in the spring once the soil reaches 65 degrees Fahrenheit.
The seed is very hard and will need a little help to germinate if planting in the spring. Nick the hard shell with the point of a knife or take a little sandpaper and sand down one side. Another method is to soak the seeds in warm water for about 24 hours before planting. Dig a hole one inch deep in an area of the garden that will get at the least six hours of sun. Plant one seed per hole spacing holes about 4 to 5 inches apart.
Seeds will grow easily and will start to send up sprouts in about three to six weeks if planted in the spring. They do not need to be fertilized in most cases. If the soil is extremely bad a shot of a liquid flower fertilizer will help. They are easily trained up a trellis. Plant them by the front porch and suspend twine from the roof to the ground and train them up the string. They will provide a privacy screen that will be beautiful and provide a lovely scent in the evening.
Since the flowers bloom at night they are not pollinated by bees as other flowers are. Instead the night flying insects do the job. Moths, especially the beautiful luna moth will pollinate them and are attracted by the beautiful scent of the flower.
It is said that the seeds of the moonflower are toxic and can cause illness if eaten. It was thought that they were a hallucinogen as some morning glory seeds have reported to be but after some tests and studies it was found that the seeds when consumed will not produce LSD effects but will make you sick.
The plants are very invasive. One way to prevent them from spreading is to remove the flowers after they have bloomed and are starting to die back. This way a seed will not be produced. The vines spread by seeds that have fallen to the ground and they germinate in the spring and take over the garden.