I recently wrote about moth orchids and solicited orchid growing tips from readers of this column.
I was more than compensated for this request by Tony Glinskas from Huntington Beach, who is a member of the “Cool Growing Orchid Society” of Orange County. Here, “cool” refers to the fact that Southern California — whose winters and nights, even in summer, are cool as compared to what you find in typical orchid habitats — still offers a climate that is compatible with robust growth of numerous orchid species.
The climate of coastal California — which is more favorable to orchid growth than that of Inland areas — while not tropical, does not experience freezing temperatures during a typical winter. When freezing temperatures do occur, they do not last for more than a few hours at a time, making it possible to grow many orchid types outdoors. This is important since nearly all orchids are not suitable as indoor plants.
According to Glinskas, “coastal California” regions of the greater Los Angeles area where outdoor growing of many orchid species is successful — recognizing that shade cloth, lath, or an overhanging deciduous tree will be needed to restrict summer sun exposure — include Los Angles County south of the Santa Monica Mountains, all of Orange County, and the coastal strip that runs up to Santa Barbara.
This does not mean that outdoor orchid growing is off limits to those residing inland. There is a San Fernando Valley Orchid Society, a San Gabriel Valley Orchid Hobbyists group, and a Riverside-San Bernardino Orchid Society, too. To locate the web sites and regularly scheduled monthly meetings of these and all Southern California orchid grower groups, as well as special orchid events and shows, visit the web site at fascinationoforchids.com.
The following quotes are taken from a summary of orchid growing that Glinskas composed in collaboration with Roberta Fox: “Orchids are generally not houseplants, except when we bring them into our living area to enjoy while they are blooming. Most orchids require more light, humidity, and temperature variation than we normally have in our homes. An important exception is the very popular Phalaenopsis or moth orchid. These like substantially the same temperatures that we do (about 60-85 degrees F), and can bloom with the light from a window with filtered sun. But even here, the light may not be of sufficient duration – if they do not get 10-12 hours of light, you may need to augment the natural light with fluorescent lighting to get the necessary duration. You may also have success with some of the ‘mini-Cattleya’ orchids in a sunny window. These have been bred to grow and bloom in a variety of conditions, including windowsills. It is vitally important for both of these groups to let the plants dry out slightly between watering – they hate soggy roots.”
Most often, orchids fail due to inadequate light. “Generally, the leaves should be slightly yellow-green in color. If the leaves are getting too yellow, decrease the amount of light. If they are deep green, gradually increase the light. Make changes gradually – sudden increase in light can cause a sunburn-like damage. If the foliage has a red cast, it is usually at the upper limit of light. Watch your plants.”
Regarding fertilization, “any balanced (i.e. 16-16-16) fertilizer” will do. “A low concentration applied regularly” is advised, at “½ or ¼ the recommended strength. ‘Once weekly, weakly’ is a good rule. Always remember to water your plants first – never feed a dry or sick plant.”
In their habitat, most of our cultivated orchids are tree dwellers whose roots are exposed to the air. This fact governs the watering practice of soaking the rooting medium (usually bark) until “water runs through the pot. This process pulls air through the root zone, and also flushes out the salts that would otherwise build up from fertilizer and hard water.”
Tip of the Week: Cymbidiums are among the toughest orchids and, in fact, resist being grown indoors. Outdoors, they flourish in most of Southern California. Where soil is sandy and fast draining, they may even be planted in the ground. “They can take temperatures down to about 28 F at night,” Glinskas informed me, “and around 100 F in the day given some shading, extra water and air flow. They require a lot of light and must have about a 20 degree F change in temperature between day and night in the fall or flower spiking will not occur. I have seen cymbidiums bloom in Hawaii because they truck them up to the high mountains for a few days to get that temperature spread.” Note: easy to grow terrestrial orchids, suitable as ground cover for partial sun to shady locations, include Epidendrum and Bletilla genera as well as select Sobralia species.
