By Norman Bezona
University of Hawaii at Manoa College of Tropical Agriculture and Human Resources Extension Service
Back in the 1960s and ’70s, the island of Hawaii was often referred to as the Orchid Isle and the Volcano Isle. Both titles always sounded more exotic and beautiful than calling us the Big Island. Today, it seems that Big Island is the official title, but when you think about it, what is so great about being big!
Besides, there are many islands that are bigger, such as New Guinea, New Zealand, Madagascar, Cuba and Hispanola, just to mention a few. On the other hand, how many islands have the world’s largest active volcano or are festooned with zillions of orchids. Sure, we are not famous for a variety of native orchids, but in cooler areas we can find lush stands of the Chinese ground orchid, Phaius tankervilleae. In the warmer wet areas, the Malayan ground orchid, Spathoglottis plicata, and the bamboo orchid, Arundina graminifolia, are common field and roadside orchids.
When it comes to garden orchids, we have more species and varieties than any other state. When we buy a flowering orchid, we can attach it to a tree or hapu‘u and it will do well with almost no care if we choose the right species for our location.
Now is a great time to learn about orchids, because we have two big orchid events.
Today is the 31st annual Kona Daifukuji Orchid Club Show at the Daifukuji Soto Mission Hall in Honalo. The show opens at 8 a.m. and closes at 2 p.m. It is your chance to buy rare orchids and enjoy the taiko drumming group as they entertain. Next weekend, the Hilo Orchid Society is having its 61st annual orchid show and plant sale, titled “Orchids around the World.” The show will take place from Aug. 2-4 at the Edith Kanaka‘ole Stadium in Hilo. It will not only feature orchids, but will even have carnivorous plants like the Nepenthes pitcher plants from Borneo for sale.
If your garden is planted to the max, consider growing orchids, bromeliads, and even carnivorous plants.
Now, let’s focus on orchids. To most people the word “orchid” immediately brings to mind the purple-flowered Cattleyas. This orchid has been and still is the most popular.
The genus Cattleya contains only 50 species in a family containing over 15,000 known species. There are a number of types of orchids that are easy to grow in Hawaii. They are readily available at garden shops and nurseries and are inexpensive. Orchids are well adapted here and many species need almost no care.
Epidendrum radicans, along with the new Epi-cats (Epidendrum and Cattleya), with their attractive pastel shades, are becoming quite popular as house plants and outdoor plantings. Epidendrums produce thin, reed-like foliage with many aerial roots. Tip cuttings with a few serial roots may be potted to increase the numbers of this plant. Flowers are 1 inch or less in size but are produced in great numbers. They are very effective for arrangements as well as for corsages.
Oncidiums are among the most valuable of the spray orchids. They are commonly referred to as dancing girls or popcorn orchids because of their shape. Flowers come in yellow and brown, white and brown, and other similar color combinations. They may attain sizes of 1/2 to 3 inches across. Many flowers may be produced on a single flower spike.
Strap leafed vandas have become very popular with growers and hobbyists. The wide range of colors, from blues to orchids to brown to whites, have attributed greatly to its popularity. Vanda flowers are long-lasting and excellent for corsages. Each flower spike will produce many flowers, several inches or more in diameter. Plants are excellent for hanging baskets containing only charcoal, but will need fertilizer applications.
The Terete vanda “Miss Joaquim” was for years the major orhcid produced in Hawaii for leis. Now dendrobiums are popular.
There are more than 700 species of dendrobium including the “honohono,” which resembles the “wandering jew” in the shape and arrangement of its leaves. The more common ones grow with ease. For the more advanced gardener, try the butterfly orchid, or Phalaenopsis. It is desirable for corsage use. Flower spikes will contain from a few to many flowers. Lavender or white flowers are most common. Flowers will average about 2 inches across and will remain open for several weeks.
For high-elevation gardeners, try the Cymbidiums. Cymbidium is an exciting genus with hybrids flowering in a wide range of colors including pink, red, yellow, green, maroon, bronze, and white, in bold vibrant tones as well as more delicate pastels and art shades. Their tall, erect, arching, or hanging sprays, durability and longevity, ease of cultivation, and usefulness as a potted plant, landscape plant, or commercial cut flower have led to tremendous worldwide popularity.
Conventional varieties require cool evening temperatures of about 55 degrees during the late fall and winter months for good flowering to take place. Such conditions occur naturally in Volcano, Waimea and upper Kona. The species and hybrids of miniature Cymbidiums require basically the same growing conditions as the larger conventional types.
A major cultural difference is that most of the miniatures do not require temperatures nearly so cool as their larger relatives. The preferred temperature range for “minis” is 70 to 80 degrees during the day followed by a 10-degree drop at night, a condition much easier to achieve in Hawaii’s lowland areas than that required by the conventional types. Nurseries are now carrying a wide variety of Spathoglottis colors. The common wild Spathoglottis is purple but now we have yellows, pinks and reds available.
To grow most orchid species, here are some hints: Most orchids require partial shade for best growth. A good rule to follow is to give the plants all the light they can stand without scorching. Excessive shade will result in lush, dark green foliage and few flowers. Too much light may produce scorched spots on the foliage. This means shade is needed immediately. Saran, lath or trees may be used for overhead shade.
Many Cattleya, Epidendrum, Oncidium and Vanda species will tolerate temperatures down to 35 degrees if in a sheltered location. But most orchids prefer minimum night temperatures of 55-60 degrees F. In Hawaii, there really is no maximum temperature for orchids if the humidity and ventilation are increased in proportion to the rise in temperature. In general, temperatures that are comfortable for people also are agreeable for orchid plants.
Watering orchids must be adjusted to the need of each plant and the media in which it is grown. Many orchids can be grown in coarse cinder or even gravel. A large plant will require more water than a small one; orchids in large pots will dry out slowly compared to plants in small pots. Grouping plants of the same size, in same size containers, and same stage of growth, permits watering at specific times rather than treating each plant individually. Orchids in active growth will require more water than those in a semi-dormant state. This means that plants will require more frequent watering during the warm summer months than during the cool winter season. Over-watering has been the main cause of death of orchid plants. Roots will rot, and the fiber becomes soggy and soft, which is harmful to the plant. Remember, never water a wet plant under any circumstances.
Fertilization and pesticides can be controversial subjects. Plants growing in cinder or rock may be fertilized with a complete liquid fertilizer of a 1-1-1 ratio. Follow the directions on the label. You may apply this mixture every three to four weeks during the year in place of a normal water application.
Insects like the orchid fly, orchid weevil and scales may be controlled with insecticides. Mites may also give you a little trouble occasionally. Again, when applying pesticides, be sure to read and follow label directions. Try to use organic types where possible.
Buying flowering orchids will give long-lasting bouquets. After blooming, you may establish them on a tree in the garden for years of enjoyment.
