Disa is a genus of beautiful plants with rather triangular flowers, often red. They require VERY different care than other types of orchids, so it's easy to kill them if you don't know what you're doing. In particular, they like it wet and should never dry out. The best-known Disa is Disa uniflora, which in South Africa is known as the Pride of Table Mountain.
The family encompasses about 6–11% of all seed plants. The largest genera are Bulbophyllum (2,000 species), Epidendrum (1,500 species), Dendrobium (1,400 species) and Pleurothallis (1,000 species). It also includes Vanilla–the genus of the vanilla plant, the type genus Orchis, and many commonly cultivated plants such as Phalaenopsis and Cattleya. Moreover, since the introduction of tropical species into cultivation in the 19th century, horticulturists have produced more than 100,000 hybrids and cultivars.
With the different orchid types, it’s important to master the watering schedule. If orchids have pseudobulbs, enlarged stem structures that store water, the orchid potting mix can dry out a little between waterings. Orchid species that are epiphytes and grow on tree branches in tropical rainforests are adapted to receiving water from daily rain, so they need more frequent watering.
The type of potting medium being used can also affect your plant's water requirements. Bark has a tendency to dry out more rapidly than sphagnum moss, for instance. It is important to remember, however, that even when the surface of your pot is dry, the root area may remain moist. Poke your finger or a regular wooden pencil an inch into the pot; if it feels moist to the touch or if the pencil looks moist, do not add additional water. The potting medium should always be damp, but not soggy—neither should it be allowed to get extremely dry.
Dendrobium is a massive genus containing more than (conservatively) 900 species. These range from cool-growing miniatures to huge specimen plants growing in hot conditions year round. The most commonly found types of Dendrobium are the phalaenopsis type (commonly known as den-phals, and named for the species most used in their breeding, which used to be known as Dendrobium phalaenopsis, but which is now known as Dendrobium bigibbum), and the nobile type (named for the species most used in their breeding, which is known as Dendrobium nobile).
Cymbidium carry tall stems with many flowers that have a more typical orchid shape. They are easily identified by their grassy leaves, and they readily form large clumps. Most common are the cool-flowering types, which need to experience a cooler winter (nights in the 40s for some time in the fall) in order to initiate flowering. Once the flowers open, they can last for up to two months or more, especially in a cool environment. These are very showy and rewarding plants, and a plant in a six-inch pot can carry three stems with 15 or more flowers each, depending on the type.
My favorite type of orchid is the lady slipper orchid because of their strange appearance. They are like no other types of flowers and have pouch-shaped lips. The mostly terrestrial and lithophytic slipper orchids include four genera—Paphiopedilum, Phragmipedium, Cypripedium and Selenipedium. But most Cypripedium and Selenipedium are not plants for the beginner because they can be quite difficult to grow under cultivation unless you live in temperate regions with Cypripedium growing wildly in your back yard!
Special thanks to David Banks of Australia, Christian Kirsch; Dr. Rudolph Jenny, Peter O'Byrne***, Eric Hagsater***, Lisa Thoerle***, Mario Blanco***, Mark Whitten***, Adam Karremans, Hakan Halander****; Daniel Jimenez***, André Schuiteman***, Dr. E.F. de Vogel, Jaap Vermeulen, Rick Barry, Dr. Guido Braeme, Rogier Van Vugt; Rene Dishong, Tom Ballinger, Mac & Helen Rivenback; Dr Rubin Salueda; Rafael Govaerts***, Padre Pedro Ortiz, Dr Leslie Garay, Vena Read, Charles Lamb, Donald Tan of Malaysia, Joseph Dougherty, Dalton Holland Baptista, Rick Cirino; Prem Subrahmanyam, ROMAN MARUSKA Czech Republic, Michael Coronado, Alejandro Taborda, Greg Butler and Oak Hill Gardens, Bill Bergstrom and Bergstrom Orchids, Donna Nash, Oliver Lenhard, D. E Vermeullen, Americo Docha Neto, Richard Korber, Carl Withner, Mark Nir, Ekkehard Schwadtke; Dr Eric Christenson, Dave Alford, Igor Zhuravlev, Tony Watkinson, David Hunt, Jean Marie Vanderwinden, Glen Ladnier, Jeffrey W. Tucker, Jorge Alejandro Paulete Scaglia, Scott McGregor, Wilella Stimmell, Eric Thiessen, Geert Volckaert, George and Kathy Norris***, David Alford, Eric Hunt, Peter O'Byrne, Allen Black, Helen Milner, Al Pickrel, Greg Riemer, Marcia Whitmore, Phillipe Musschoot, Wilford Neptune, Jean-Claude George, Tony Walsh, Greg and Kerri Steenbeeke and their Orkology Kreations Website, Jim Hamilton, Robert Fuchs and RF Orchids, Gene Monier and JEM Orchids, Jerry Bolce, Andy's Orchids, Stephen Jones, First Ray Orchids, Robert Weyman Bussey, JEM Orchids, Carlos Hajek and his Peruvian Orchid Page, Bill Morden, David Morris, Noble Bashor, Patricia Harding, Nina Rach, David Haelterman; Craig Cooper, Rocky Giovinazzo, David Friedman, Bill Pinnix, Troy C. Meyers, Linda's Orchid Page, Pierre-Alain Darlet*, Guy Cantor, Tropical Orchid Farm in Maui, H&R Nursuries, Lois Greer, Ichiro "Haru" Ohsaka and his Bulbophyllum Page, Mauro Rosim from Brazil, A World Of Orchids, Bruce Norris of Canada, Nick Doe, Neville De La Rue, Nelson Barbosa Machado Neto, Jeff Aguillon, Dale and Deni Borders, Eka Mulja Tjipta, Rick Barry, Manfred Schmucker, Uri Baruk, Mike and Candy Joehrendt, Dan and Marla Nikirk, Walter Orchard, Christer Carlson; Guillerrmo Angulo, M. Max, Paula Vagner, Tennis Maynard, Greg Allikas, Malcolm Thomas, David Morris, Jacques Deschenes, Lourens Grobler; Gary Yong Gee; José Castaño Hernández; Judd and David Janvrin* for their photo and text contributions.
Now that we’ve laid out the general guidelines, we will explore the ins and outs of how to water phalaenopsis orchids by answering some of the questions you’re sure to have if you are new to the world of these intriguing plants. So read on to learn about different aspects involved in understanding how to water phalaenopsis orchids to encourage healthy growth and prolific flowering!