The flowers of this orchid cactus, (Epiphyllum oxypetalum) bloom at night and last only about twelve hours until they wilt.
A zig-zag orchid cactus with pink flowers.
Another orchid cactus with pink flowers...
The orchid cacti (genus Epiphyllum) are about 20 species of primarily epiphytic (grow on plants) or lithophytic (grow on rocks) cacti from tropical America. Most orchid cacti have broad, flat, leaflike stems that are often zig-zaggy or at least with lobed margins. In older plants the main stems often become woody. Orchid cacti usually do not have any spines, and they never have true leaves.
Epies do have large, showy flowers, usually white, but some species have red or yellow flowers. The flowers are funnel shaped, often sweetly fragrant, and range from three to twelve inches (8-30 cm) in length. Around here in North Florida, they are visited by hummingbird moths. Typically, each flower blooms for just one or two evenings, but some species have diurnal flowers and some have flowers that stay open for a week or more. Edible, but small, red or purple fruits are the norm.
Some of the cacti known as night-blooming cereus are actually species of Epiphyllum. But that’s OK; night-blooming jasmine (Cestrum nocturnum) is not a jasmine (Jasminum sambac, for example).
The various wild species of orchid cacti occur in rain forests in Central America and northern South America and in the West Indies.
Orchid cacti are easy to maintain. Grow them in a fast draining, slightly acid potting mix with about a third perlite or coarse sand to defend against compacting. Keep moist. Epiphyllums flower best when they are potbound, and given a fertilizer that is low in nitrogen and high in phosphorus.
Light: Most species of Epiphyllum do best in bright filtered light or partial shade. They do not like direct full sun, but morning and late afternoon sun are okay. Moisture: Although epies are members of the cactus family, they do not grow in deserts and they thrive in a humid environment. Orchid cacti need a lot more water than desert cacti. Water frequently. Soak the soil until water runs out the drain holes and don’t let the soil dry out between waterings. (But don’t allow the roots to remain soggy, either.) In winter, when the cacti are relatively dormant, you can reduce watering. Hardiness: USDA Zones 10-11. The orchid cacti are tropical plants and none can tolerate frost or freezing temperatures for very long. Most do best when temperatures don’t fall below 50°F (10°C). On the other hand, orchid cacti can’t tolerate extremely high temperature over 100°F (38°C) either.
Propagation: Epies are easy to start from cuttings. You get the best results if you cut a short length of stem and let it rest in a dry, dark place for a few days until the cut end heals over. Then stick the cut end an inch or two (2.5-5 cm) into the potting mix. Don’t water the new start for two weeks.
An Epiphyllum oxypetalum orchid cactus in bloom.
A trio of fragrant orchid cactus flowers are still fresh and fragrant in the early morning hours.
Orchid cacti are popular house plants. They are easy to maintain, have interesting, usually striking (sometimes unkempt?) foliage, and produce beautiful flowers, if only for a few days at a time. When temperatures stay above 50°F (10°C) or so, grow orchid cacti in hanging baskets under a tree or on a shaded porch or patio.
I have several epiphytic cacti of various species and genera (Epiphyllum, Rhipsalis, Zygocactus, etc.) that thrive in hanging pots suspended from the branches of a large magnolia tree in the front yard. They get mostly shade and they get watered automatically every morning with a timed sprinkler. Of course, I bring them into the greenhouse in the winter. I also grow epies in old turpentine pots (modified with drain holes) that hang on the screened porch.
Although there are only 20 or so natural species, there are thousands of Epiphyllum hybrids; many are descendants of the crenate orchid cactus (E. crenatum), a species with large white flowers that open during the day. The Epiphyllum Society of America is the official registry for orchid cactus cultivars. As of the latest edition of their Epiphyllum directory, there are more than 7000 named orchid cactus hybrids and cultivars recognized.
The goose-neck cactus (aka broad-leaved epiphyllum, E. oxypetalum) is a popular species that has strongly fragrant flowers which bloom for one night only. Orchid cacti are related to the Christmas cacti, genus Zygocactus.
Apparently some species of Epiphyllum have been used for hallucinogenic purposes.