Originally published in the Davis Enterprise, February 24, 2005
With more than 25,000 species, found on every continent except Antarctica, orchids are fascinating to collectors. There's an astonishing range of specialized growing habits and pollination relationships involving highly modified flowers. One is pollinated by male moths which try to mate with the flower, since it resembles the female moth. An Australian species, Rhizanthella, grows and blooms entirely underground (it wasn't discovered until 1959 when a farmer accidentally plowed one up). Orchids are a truly weird and wonderful group of plants!
The showy flowers make them popular with even novice gardeners. And the lore and mystique of orchids figures prominently in classic literature and film. Where do they come from? How do we grow them here? Which can grow outside? Which are easy as houseplants? Will they bloom again indoors? When? And the infamous
.why did it die?
Orchis, as every new horticulture student knows, means testis--referring to the paired underground bulbs of Mediterranean orchid species known to the Theophrastus, the Greek 'Father of Botany'. Medieval doctors, using the Doctrine of Signatures, believed that the shape or structure of a plant indicated its medicinal use. So the walnut was good for the brain, bloodroot (named for the color) was good for anemia, and the orchid was good for
virility. (One wonders what they would have done with cactus--medieval Rogaine?) There are a few commercially important species: the seed pod, or bean, of the Vanilla orchid is the source of true vanilla.
Europeans had a pretty mixed history with orchids at first. There were only a few European species known, and though their flowers were reasonably pretty many had offensive odors. The finger-like roots of European species led to the attractive common name of 'Dead Men's Fingers' (Hamlet, IV, vii). There were some dietary uses. The gelatinous material derived from some orchid tubers has been used for glue and treatment of croup and diarrhea. Salep is a 'wholesome and nutritious drink' (Mrs. M. Grieve's A Modern Herbal) made from the tubers. It was sold on the streets of Turkey and London until coffee came along. 'Accompanied by a slice of bread-and-butter at a halfpenny
an ideal breakfast for a chimney-sweep', according to Charles Lamb.
These European types were terrestrial ('grow in the ground') orchids, which have tuberous roots. We have some species in North America of this type--hardy perennials such as Bletilla which grow easily in the garden and bloom in the spring. But these aren't what you're thinking of -- they don't have large, exotic flowers. The popular Cymbidium orchids with long spikes of flowers in the spring are 'semi-terrestrial', so we plant them in a mix of half soil, half bark. These are not tropical species, and are actually hardy enough to grow outside here in a location sheltered from extreme cold or heat. In fact, they require cool temperatures in fall to set buds and flower properly.
Most of the early cultivated orchids in Europe were brought back from steamy places such as Bangkok, and growers assumed that they wanted hot tropical conditions. But in fact, most had been brought down from the mountains for sale in the port city, and preferred more moderate conditions. So they often rotted.
Are they expensive?
The tropical species became hugely popular nonetheless in England, Holland, and Germany, with an orchid craze of the late 19th century reminiscent of the tulip mania of the 1600's. Together with the slow methods of increasing orchids--chiefly by dividing one plant into two or three--this contributed to the reputation of orchids as fussy plants only for the wealthy. But modern propagation techniques have made it possible to multiply them very rapidly, greatly reducing the cost.
How do we grow them?
The majority of the popular types grow in semi-tropical areas hanging on trees (epiphytes) with their roots in loose leaf litter, or clinging to rocks (lithophytes). Some grow in leaf litter on the forest floor (saprophytes). All of these types get most of their moisture from the high humidity and frequent rainfall of their habitat, and most of their nutrients from the steady decomposition of leaves, bugs, and other things that collect around their roots.
So to grow these types of orchids we mimic these conditions. We plant them in a very fast-draining medium such as fir bark, water frequently (a couple of times a week, typically) and feed them lightly and often. I suppose you could gather leaf mold and dead bugs and frogs and bird droppings to add to the soil mix, but most people find it tidier to fertilize with soluble plant foods, or apply a slow-acting product such as Osmocote.
Can they grow in your house?
The terrestrial types such as Cymbidium prefer to be outside in light shade. The tropical types will grow indoors in the brightest light you have other than direct sun. They need even moisture but don't want to be soggy (most problems result from root rot). It is often suggested that you mist them frequently or set them on a tray of pebbles above water. These aren't really effective ways to increase humidity, but the fact is that most orchids aren't that fussy about humidity.
Do I need to repot my plant?
They grow and bloom best if they are a little rootbound, and can tolerate being very rootbound. Overpotting them (putting them in a pot that has too much extra soil around the roots) increases the risk of overwatering. But the plants you buy are often very, very rootbound. Repot them if necessary when you see new root growth beginning, usually in the spring or early summer. If in doubt, repot in spring. It's not difficult, but if you are new to orchids garden centers can help you repot them.
Will they bloom again?
Some bloom annually (Cymbidium only bloom in the spring), some bloom off and on at any time. Most have a rest period after bloom, lasting from several weeks to months. The easiest large-flowered types are Dendrobiums, Phalaenopsis, and Vanda. These have blooms which last a long time, and tend to rebloom readily.
But it's important to know that orchids generally won't bloom again on the same growth in the same year. So you need them to keep putting on new growth, in the bright warm conditions they (mostly) prefer, in order to keep getting flowers. Because the bark they're in doesn't hold nutrients, the regular light feedings are important to keep that new growth coming.
Some old advice is easy to remember. Although written about Cymbidiums, this can apply pretty readily to other types as well:
In spring don't put them out of doors,
In summer don't expose to too much sun,
In autumn don't keep them too dry,
In winter don't keep them too wet.
-Jo-an Matsuoka, 1728.
Click here for an Orchid Care Chart!
© 2008 Don Shor, Redwood Barn Nursery, Inc., 1607 Fifth Street, Davis, Ca 95616
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