March 4, 2009
Dennis Westler, the Orchid Doctor, is a horticultural specialist who fields orchid queries at the San Francisco Orchid Society's website. He helps orchid growers from around the world tackle a diverse range of plant-related issues. He's also the organizer of the annual Pacific Orchid Exposition in San Francisco, this year held from March 5 to March 8 at Fort Mason's Festival Pavilion. I had the opportunity to ask Mr. Westler a few questions about orchids, their cultivation, and about this year's expo theme: Green ... With Envy.
1) What originally drew you to the study of orchids?
I should mention that although I am called the Orchid Doctor, my educational experience is in natural resources, land use planning, and landscape architecture. As an orchidist I am an autodidact. I started doing “Orchid Doctoring” at our shows, at meetings and in private consultation when I realized I enjoyed the problem-solving aspect, and was good at teaching techniques.
I started growing orchids in 1974, at the height of the houseplant craze. Having been through most of the common houseplants I wanted a challenge. I saw a Phalaenopsis amabilis (the great granddaddy of the big, elegant, white hybrids) and fell in love. Because I had studied plant physiology and forest ecology in college, the extreme form and adaptation of both the plant and the flowers really appealed to me.
Although people often kill their first orchids, I did well with it, blooming it every year till the late 80s when I gave it away. That plant started me acquiring more, buying books, asking questions, visiting habitat and so on.
2) To what do you attribute the public's fascination with orchids?
Several things really. The mystique for one: the fact that for so long they were the flower of the rich and royal. The exoticness -- that they come from far off, tropic places. Most people are not familiar with their native orchids. Their beauty, and for those who get hooked, the weird and bizarre ones. Then there is the fact that they are seen so much in advertising and in home and garden magazines. They have come to represent good taste. And more and more, it's the same things that attracted me.
3) This year we celebrate the bicentenary of Darwin's birth. Can you tell me a bit about how Darwin's studies influenced scientific understanding of these plants?
Darwin, in fact, wrote an entire book of his observations on both temperate zone orchids, and the ones that he saw in the tropics, focusing specifically on pollination mechanisms.
One of the most important things that Darwin realized about the orchids was the co-evolution of flower and pollinating insect, and the pollinator specificity of orchids. In many cases only one species of insect can pollinate a specific orchid. And that flower is often irresistibly alluring to that insect.
The famous example was Darwin’s statement -- after studying the Madagascan Angraecum sesquipedale -- that a moth must exist with a tongue as long as the enormous nectar spur of the flower (up to 18 inches). Entomologists scoffed, but 40 years later the moth was found, just as Darwin predicted. He was fascinated by the apparent pollination strategies of orchids, and many people still are. The orchids' use of sexual attractants, deception, and traps of various sorts is amazing.
One example of this is the various ladyslippers which trap insects like a pitcher plant. There is only one avenue of escape which forces the insect to either pick up pollen or deposit pollen picked up previously. Another example is the European Ophrys. It has a lip that resembles a female wasp or bee, and actually produces the same pheromone that the female would. They are irresistibly attractive to the males who pollinate the flower by pseudocopulation. Our docent tours at the Orchid Exposition point out flowers with unusual pollination strategies.
4) Is there anything to suggest orchids have developed or are developing adaptive strategies to deal with stresses such as reduced numbers of their specific pollinators?
Generally, these things occur too quickly for natural selection to be of much good. If there is another species that occasionally pollinates the plant successfully, the species has a chance to adapt. Or if the species exhibits cleistogamy (auto-pollination achieved by the flower without an insect visit), it may also persist and adapt to other available pollinators. Generally though, when an orchid's pollinator disappears, so does the orchid, at least locally.
5) What are the most common mistakes people make when trying to grow orchids? And, are there any orchid absolutes? Or is the care of an orchid entirely species dependent?
The most common mistakes people make when growing orchids are not giving them enough light, and not watering them properly (overwatering, or mistakes in watering technique). Not repotting properly or frequently enough runs a close third. After that, is a failure to understand temperature requirements.
The only absolute is that care of the root system is paramount in growing healthy orchids. The care that individual species, or related groups of hybrids require (in terms of temperature, light, watering frequency, and dormancy) varies wildly within the family. Among the orchids commonly grown, for example, the temperature range some require to grow and bloom would kill others.
6) Is there anyone who shouldn't try to grow an orchid? That is, is orchid cultivation better suited to certain qualities or personalities?
Clearly, there are people with no interest in plant husbandry. I think they would just find orchid growing frustrating. Among people who enjoy caring for plants, I think there is an orchid to fit every temperament -- providing you have the right light, and the desire to learn. There are even those orchids that literally thrive on neglect. The genus Eulophia comes to mind. Some of the Eulophia species grow in deserts, and are usually seen in Cactus and succulent collections rather than orchid collections. The perfect orchid for some people. Cattleya is another genus that works well for people who don’t like to fuss and don’t water frequently.
