'SELECT' x sib 'MAKAWAO'.
|Pleurothallids: Wave of the Future?|
by Jeffrey Parker (2002-06-01)
Our company is perhaps best known for our seed-grown species of Cattleya, Dendrobium, and Stanhopea-relatives, and we will continue to emphasize them. But several of you have noticed that we are adding more species in the Pleurothallidinae each year and have requested more information.
What are pleurothallids and why grow them? The pleurothallidinae is a large and fascinating orchid subtribe composed of around 32 separate genera. It is the largest subtribe in the orchid family, with at least 4000 species. It is a subtribe of the Epidendreae. These are New World orchids, found from Mexico to Brazil. Many are from the slopes of the Andes. The plants vary in size, from tiny to huge. These orchids have no pseudobulbs, have only one leaf per growth, and are generally "tufted" in habit. Flowers can be tiny or quite large in relationship to the plant size, and often emerge from the center of the leaf. The best known genus of course is Masdevallia, first gaining popularity in England in the Golden Age of Orchids. B.S. Williams writing in 1885 said "...more than 100 species having been discovered, most of them within the last few years. Some of the species are very distinct and brilliant in color, which renders them especially valuable for decorative or exhibition purposes... which furnish colours that add much to the brilliancy of the display in our Orchid houses when they are in flower, and enrich our collections by the contrast they afford to other types of this wonderfully varied family." In Williams' time, most pleurothallids were called Masdevallias, and that is the only genus of the family covered in his landmark book, The Orchid Growers Manual. By 1925, Sanders Orchid Guide covered 5 genera; Masdevallia, Restrepia, Scaphosepalum, Stelis, and "Physosiphon".
It seems natural to us that interest in this family would increase as we begin the current decade. Beginning in 1970, much attention of orchid enthusiasts has been directed at another unrelated family, the Bulbophyllinae, a large group of mostly Asian orchids with bizarre and fantastical flowers. Pleurothallids represent yet another almost endless avenue for those fascinated by the weird and wonderful, and for those fighting to call attention to Earth's fragile and rapidly-declining biodiversity. Besides the endless variety of whimsical plant and flower forms, many pleurothallids offer the advantage of small or "miniature" plant size. As the cost of energy increases, growers are looking for ways to get more out of their smaller growing spaces. 100 or more different pleurothallids could fit in the same amount of space occupied by a few large cattleya plants! Another advantage is that many pleuro's flower over and over from old and new racemes. Attractive plants and ease of propagation are other inducements to grow these species. Finally, new species are still being discovered all the time, adding to the excitement.
Only 10 years ago, popular belief was that "we can't grow pleurothallids in Hawaii"! The feeling was that it is too warm here. Even we believed that. A turning point came for us when a customer of ours who had visited us, Joe Chambers of New York City, sent us a gift box of species from his collection. Three of the plants were pleuros, a pleurothallis, a restrepia, and an unidentied yellow Colombian scaphosepalum. After a few years it became clear that the 3 species were not only surviving -- but doing well! We were on our way.
Of course the belief that Hawaii is too warm for pleurothallids is silly. Almost any temperate, subtropical, or tropical climate can be found on Hawaii's high mountains from sea level to over 10,000 ft. More important for the reader is that many pleurothallids are actually intermediate or warm growing. Of course, some species are truly cool-growing. A sign that your climate is too warm for a particular pleuro species would be that the plant grows okay and produces offshoots, but never flowers. One of those first 3 plants was Restrepia striata, and it grew very well and flowered profusely. This led to us trying more restrepias, until finally we bought every restrepia species that was offered. Virtually all restrepias have survived and flowered for us, and that is why I often mention that they serve as a good introduction to the world of pleurothallids.
Why aren't more species enthusiasts growing pleurothallids? How does one grow these orchids and what are the problems? "There are [pleurothallid]species that thrive in warm, intermediate, or cool greenhouse conditions; some can be grown dry, while others must be grown wet." (Pridgeon, 1992) Well, that certainly doesn't help very much, does it? In general, the majority of species can be grown under intermediate temperatures. In nature, most species come from wet or humid habitats. Some hobbyists find that sufficient humidity is the main problem they face. Remember -- these species have no pseudobulbs for the storage of water. Windowsill growers and greenhouse hobbyists have devised methods for keeping up humidity. I suggest that you discuss this with experienced growers in your area and consider joining The Pleurothallid Alliance, an organization that puts out an excellent newsletter in which many home pleurothallid enthusiasts discuss their methods in detail.
It seems that many growers prefer to cultivate these species on plaques or "mounts", to provide for more air movement and to allow the plants to tolerate more frequent misting. We have grown our plants this way, but now we have gone back to pots, employing what I call the "wet roots, dry leaves strategy". We use mainly New Zealand sphagnum moss in small plastic pots. When soaked and kept in a plastic pot, sphagnum moss retains moisture for a long time. We soak the plants and then don't water again for about a week. This varies, depending on what the weather outside is doing. We lost plants by overwatering, especially in the warmer summer months. So, although most pleurothallids come from very wet places, overwatering when they are in plastic pots of sphagnum doesn't work. What works in nature may not work in artificial greenhouse conditions. All pleuros in pots on our tables get repotted once-a-year. Even mounted plants should be remounted periodically. The annual repotting works well and this is the natural time to divide your plants, should you so desire. We stick with the annual repotting even when using our alternate mix of fine fir bark and perlite.
Other tips: When using dried NZ sphagnum moss, it is important to pre-soak the moss for several hours, preferably overnight before use. It takes on a completely different texture after long-soaking. Learn how to pot so that there is a 1/2" "airspace" at the bottom of the pot -- this provides extra drainage and helps to keep the moss from becoming sodden. It is important that the consistency of the moss in the pot should be slightly-tight, not loose or very-tight. Since pleurothallids are more sensitive to fertilizers than your other orchids, cut down your fertilizer strength if possible or reduce the frequency of feeding. A survival strategy for periods of hot weather is to water less. This might make your plants look dessicated and wilty for a while, but they are less likely to rot.
The whimsical and entertaining nature of these orchids should not be overlooked and the incredible variety in the species demands our investigation. We hope you will try some too.
Pleurothallis marthae x
RESTREPIA dodsonii var.
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