By Norman C. Bezona
University of Hawaii Cooperative Extension Service
College of Tropical Agriculture and Human Resources
After last Sunday’s article on this weekend’s Hilo Orchid Show, we received a number of requests for information on the carnivorous pitcher plants mentioned in the column. Although the focus for the show is orchids, I mentioned that the Nepenthes Pitcher Plants from Borneo also make a great addition to the orchid garden. Today is the last day of the show at Edith Kanaka‘ole Multipurpose Stadium, and you can still get the scoop on Nepenthes if you get there in time to visit with Sam Estes, who specializes in these amazing plants.
My limited experience with Nepenthes proved they are easy to grow in the Kona Cloud Forest, but to learn more I visited with Sam in Leilani Estates to see what I could learn to share with others.
Simply, there are high-elevation species that grow above 3,000 feet and prefer cool temperatures, and there are lowland species that do well below that elevation. Most hybrids will thrive in temperatures between 60 and 90 degrees.
They are easy to grow, but prefer a moist, well-drained medium such as sphagnum, hapuu or coconut husks. The secret seems to be that they won’t tolerate poorly drained medium and at the same time should not be allowed to dry out.
Chemical fertilizers are to be avoided. Dilute organic types are better. Insect pests are few because they usually get eaten by the plant!
To my amazement, Sam showed me hundreds of hybrids, including one giant that was capable of digesting lizards, frogs, and even mice! If you don’t get to the orchid show today to see the Nepenthes, you can obtain information on the web at www.leilaninepenthes.com.
Now back to orchids and other plants not requiring typical soil conditions and that can be grown as “air plants.” This includes orchids, ferns, bromeliads and even cactus that grow on trees.
This group of unusual tropicals is technically referred to as epiphytes. In wet tropical regions, almost any plant can grow on trees. Many Ficus or banyan types, Vireya Rhododendrons, Clusias and even gingers may start their life as epiphytes. Although epiphytes grow attached to shrubs and trees, they are not parasites, since they do not take their nutrients from the plants on which they grow. Air plants have some of the most beautiful flowers and unique foliage in the plant kingdom. They generally require less care than most other ornamentals. Many folks think air plants are difficult to grow, but this is not the case. Our tropical climate is ideal for air plants that are virtually impossible to grow outdoors anywhere else in the United States. Here, many grow with almost no care.
Orchids and bromeliads are probably the most well known of the epiphytes. Many species have been introduced. If you have a tree or lanai in which to hang pots, you can have flowers the year round. All it takes is common sense, water and fertilizer. When buying orchids and bromeliads, it is important to get healthy plants. Ask the grower or nurserymen about the particular species and its care. When grown in containers, they will require repotting every two or three years. To avoid the problem of repotting, many gardeners remove the plants from the pot and attach them to the branches of a tree. Rough-barked trees like paperbark, monkeypod, calabash, ohia and African tulip are well suited to epiphytes.
The epiphytic ferns and cactus may be also grown in pots or on trees. The secret of success is to be sure they have good drainage. Fertilize lightly every two or three months to keep plants in active growth. But if plants are attached to trees, this is not required. Several brands of orchid fertilizer are available.
They are satisfactory for other air plants as well. These are especially formulated and when used according to directions will give excellent results. Disease and insect problems are few. If they do occur, our local garden supply dealers have fungicides and insecticides to quickly control the situation.
Give the air plants a try in your garden. Start with easy types such as bromeliads, like Tillandias, Billbergias, Guzmanias and Aechmeas. Staghorn and Resurrection Ferns are easy. Dendrobiums, Epidendrum and Oncidium orchids will thrive on a minimum of care. From there, go to the more exotic Cattleya and Moth orchids. Local nurserymen can give you quite a few ideas on the types to grow and ways to grow them.
Bromeliads, cactus and succulents may do with very little water or fertilizer. Ferns and orchids should be watered every few days and fertilized about once a month.
Some folks worry that insects may breed in the center of bromeliads, especially mosquitoes. These insects can be more than a nuisance since one species of mosquito is even a vector for dengue fever. That is why natural insect control with lizards, amphibians and birds makes good sense.
It also makes the garden more interesting. Anole lizards, Jackson chameleons, and geckos, especially the gold dust day gecko, add to the tropical magic of our gardens. Many common birds feed on insects, so including a bird feeder in the garden also adds benefit and beauty. Flushing the center of bromeliads with water occasionally washes out potential mosquito homes. There are also biological insecticides that are safe and specific for mosquito control. Of course, don’t forget to have a few hungry carnivorous Nepenthes Pitcher plants in the mix to finish off unwanted pests!
There are many books on orchids and their culture. You might also consider joining one of the local orchid clubs to learn from other enthusiasts. Local Outdoor Circles like Kona, Waimea and Waikoloa are another way to meet folks who enjoy all kinds of gardening. The Kona Outdoor Circle also has a great horticultural library open to the public. For further information on air gardening, contact the UH College of Tropical Agriculture and Human Resources offices in Hilo or Kona.