How to Grow Moonflowers (Ipomoea Alba)

by Matt Gibson

The moonflower (also known as devil’s trumpet and thorn apple) is a lovely trumpet-shaped, self-seeding, nocturnal annual flower and a wonderful addition to your flower garden. A North American native, the moonflower was founded in Jamestown, Virginia, and its botanical name is ipomoea alba. The moonflower’s glorious blooms unfurl beneath the light of the moon from which it gets its name, and as the sun rises, the long white petals curl up and the bud closes, hiding its beautiful blossoms until the night comes again.

Though technically a perennial flower in tropic and subtropic regions, gardeners in climates with cold winters can grow moonflowers as annuals. Though usually planted with intention, the weed-like moonflower can potentially become quite invasive. After its blooming season ends, the moonflower vine begins to develop thorny pods. The thorns start off as soft and harmless little bumps but quickly grow into sharp talons that can do some serious damage to ungloved gardeners. Once ripe, the pods burst open and rain down hundreds of seeds for the next year’s plants.

The moonflower has a dark sibling too, and though similar on a surface level, this plant’s uses are not just about glamour and good looks. Datura innoxia is another species that is commonly referred to as moonflower, as it looks similar and only blooms at night. However, it is a strikingly different plant.

Though its oils are often used in perfumes, when its petals are crushed, they produce a pungent and noxious odor described as reminiscent of rotten peanut butter, which gardeners agree is best avoided if possible. If ingested, the datura innoxia species of moonflower can be quite deadly, quickly affecting the nervous and cardiovascular systems.

Therefore, if you are planting the Datura innoxia type of moonflower in your garden, be sure to place these plants out of the reach of curious children and prowling pets. Because the two species share a name and many commonalities, the ipomoea alba moonflower is widely and incorrectly labeled as a toxic flower, though it has no toxic properties.   

Moonflower Varieties

There are quite a few night blooming flowers that are also commonly referred to as moonflowers, including Hylocereus (a night blooming cactus), Datura, Ipomoea, Mentzelia (or evening star), and Oenothera (or evening primrose). The most frequently cultivated varieties of moonflower are Ipomoea alba and Datura innoxia. This article focuses on the Ipomoea alba, and not on its highly toxic sibling, Datura, less frequently planted in gardens. However, to fully separate the two species in order to avoid any confusion between the two, we will describe the characteristics of both in full detail. 

Ipomoea alba: Most comfortable in a tropical or subtropical climate, Ipomoea alba is a wild growing vine that can grow from 15 feet to 90 feet in length (or height if the vine has a tree or structure nearby on which it can climb). At night and in full bloom, moonflower blossoms can be as large as six inches in diameter. A lesser known fact about the ipomoea alba is its incredibly short lifespan. During the blooming season, this variety of moonflower opens up at night and in the morning, it closes up and dies. This is not commonly known, however, because a new bloom grows up in its place during the afternoon.

Datura innoxia: Unlike the Ipomoea alba, the Datura innoxia species of moonflower only grows to about four feet in height, but has a very similar looking bloom. The blooms do not die and reproduce daily, but they do only open and reveal their full luster only once night has fallen. The entire plant is covered in soft, short, gray hairs, which give the whole plant a grayish appearance, even though the stems and foliage are green. Whereas the Ipomoea alba blooms look like they just fall open in one swift motion, the Datura innoxia opens at a slower pace and seems to twist itself open instead of dropping open. 

Growing Conditions for Moonflowers

Moonflowers do not need a lot of ground space, as they love to grow upward. If you provide a support for the vines, such as a trellis, the vines will twine around it and easily grow as high as 20 feet (or even higher). Moonflowers grow year round in zones 10-11, but in cooler zones, they can be grown as annuals. The vines are practically care-free once started and are easy to grow from seed. Moonflowers don’t require full sunlight or well fertilized soil. In fact, they will grow wildly in just about any area. However, better soil and prolonged exposure to the sun will increase the amount of blooms that you will see each season.  

How to Plant Moonflowers

In cooler areas, plant moonflowers once the ground has reached a temperature of 60 to 70 degrees Fahrenheit. Crowding the root systems in a small container may encourage early blooms. However, moonflowers grow perfectly well in large containers or directly in the ground. In warmer climates, mulch the roots, and in colder climates, dig them up for winter storage.

Care of Moonflowers

Water small plants often, and continue to provide water as moonflower vines grow, especially in cases of drought or extreme heat. Fertilize with a high phosphorus fertilizer at half strength to encourage more blooms. Too much nitrogen fertilizer will curtail blooming and focus growth on foliage, so be sure not to fertilize with a high nitrogen fertilizer unless the greenery is your goal. Feel free to pinch back flowers at the top of the vine to promote more blooming at the base.

Garden Pests and Diseases of Moonflowers

There are no major issues with garden pests or diseases of the moonflower vine.

Indoor Bouquets

Because moonflowers only bloom at night and have such a short lifespan, cutting them down for indoor arrangements is a waste of time. For a similar looking flower that will work wonderfully displayed indoors, try morning glories [https://www.gardeningchannel.com/how-to-grow-morning-glory/].

Videos About Growing Moonflowers

Here’s a six-minute video that’s all about the moonflower:

Here’s a beautiful time lapse video of the moonflower blooming:

Want to Learn More About Growing Moonflowers?

dengarden covers Moonflowers: Night Blooming Plants

Gardening Know How covers Growing Moonflowers

Plant Care Today covers How to Grow Moonflowers

The Spruce covers Growing Moonflowers in Containers