Some Cool Orchids

By Clement Kent

 

Itís just past New Years and the orchids are cool, really cool. Thatís because Iíve managed to kill all the ones that need warmth-and therein lies a story.

I have 3 kinds of orchids which bloom for me, one kind abundantly, one somewhat, and one rarely. Although I grow lots of other plants, I am decidedly not an orchid expert. However, the beauty of the flowers and ease of care has seduced me into becoming a beginning amateur of those orchids which grow well under cool conditions. If you have a warm, well insulated house then thereís a whole other group of orchids you can grow which I canít. But if you, like me, have spots with less than high-tech windows and pockets of shiversome air which is above freezing but less than 20įC, you can grow them too.

Big and Beautiful - standard Cymbidiums

My easiest and most rewarding orchid is a "standard Cymbidium". The genus Cymbidium is a large group of orchids found mostly in southern Asia. There are larger ones (the "standards") that tend to be found in mountainous terrain in Burma and Thailand, and smaller ones (the miniature Cymbidiums) which are found at lower elevations. Under my conditions, the standards are the easiest to grow. For a warm household, go for one of the miniatures instead.

Most tropical orchids grow high up in the forest canopy, on the branches of trees. But standard Cymbidiums grow on the ground, in the partial shade and loose leaf litter of montane forests which almost, but not quite, reach freezing temperatures on winter nights. Their soil-dwelling habits make these big orchids easier to grow for the amateur since they are somewhat less fussy about watering and potting.

The variety label is lost, sadly, but my big Cymbidium has 3 foot long stalks which carry about a dozen buds. Those at the bottom of the stalk open first. As they first expand, their color is apple green. After a few days the petals turn a lovely golden green hue. The central structure (the lip and column) is spotted with small red dots. Each bloom is about 4 inches across - one is big enough for a corsage. About the time the flower turns gold a wonderful honeyed scent wafts out. In the morning when the air is still our whole kitchen smells like a cross between an apple orchard in bloom and a honeysuckle bush in June.

In a room which is not too warm, especially at night, and when the plant is not exposed to direct sun while in bloom, the flowers will last almost a month if not cut. They also make a delightful cut flower for a large vase, lasting about a week if cut just after reaching maturity.

When the flowers fade the stalk should be cut off and the plant moved back to the growing area. I use my cold greenhouse (my basement steps covered with Plexiglas) where the temperature hovers around 5-10įC until March. By April the greenhouse is heating up and the plants should be fertilized (half-strength 20-20-20 or organic equivalent) every two weeks until July to promote new growth. In May they are moved outside and covered with a muslin cloth for a week so the leaves donít burn in the strong sun. Gradually I remove the cloth, although I leave the plants where a porch railing and slats give them shade at noon. They get full sun for a few hours in morning and late afternoon until it begins to get cooler in September. Then I move them into a spot on the porch where they get full sun and keep them there right up until frost comes. At the end of October or thereabouts back they go to the cold greenhouse, which must remain cool to stimulate formation of the flower stalks.

The combination of stopping fertilizing in August and cool, sunny days and crisp nights usually brings visible stalks by November or December. Bloom time can be anywhere between early December and February. As the stalks are developing they tend to sag under their own weight. It can be very disheartening to find half or all of a big stalk broken off, and the warmer they are at this time the higher the risk. I lost parts of several stalks this year due to the lovely warm and sunny weather in November and early December. By this time my greenhouse is sealed up and it overheated between noon and 3:00. Stakes for the stalks would have helped but as they are usually not necessary I didnít bother.

Repotting should be done every two to three years and is best done in April or early May. I use a combination of 1/3 to Ĺ regular potting soil such as Loblawís "Magic Soil", plus some bone meal, some charcoal, and any good drainage additive - very coarse sand (not fine builderís sand!), perlite, or the like. If you can get it, well-decomposed rotted leaves can be added - as much as 25%. My plants are kept in large 10-12" diameter plastic pots. Pull out the whole plant, put it down, and use a pitchfork or your hands to tear apart the clump into two or at most three pieces. Be brutal! Discard the dormant "back bulbs" without leaves, and plant the divisions in the center of new pots. Donít fill the soil level right up to the base of the pseudo-bulbs; leave about an inch clearance. I fill this inch with very coarse bark to ensure air can reach the roots and the pseudobulbs wonít rot. The soil mix should be neither wet nor dry when you repot.

After repotting put the plants in a shadier spot and donít water for at least a week while they reestablish themselves. Then treat them as described above. You will get less bloom, maybe even none, the year after repotting, so I try to go at least three years before dividing again. On the other hand, you will soon run out of space for these beautiful but large plants so will have the pleasure of giving some to friends or the Hort spring sale!

The leaves are very decorative at all times, about 3 feet tall, dark glossy green. Very few pests seriously bother them. If they are too dry and in too much sun you might get some spider mite - simply moving the plant to a shadier spot and spraying the leaves with water will solve the problem non-chemically. Scale insects can be an issue; wiping the leaves with alcohol gets rid of them.

The biggest pest problem by far for these and all orchids are nasties at the roots. Donít put the plants on the ground when you move them outside - raise them up to keep the snails, slugs, and sowbugs out. Even earthworms can be destructive! When you bring the plants in for the winter a small amount of slug and cutworm bait on the surface of the pot, repeated over several weeks, will eliminate any unwelcome passengers.

The general rule for watering all orchids is to use room-temperature water that has stood for some time to let the chlorine escape. Soak thoroughly, then let the pot drain completely- never let them stand in still water. Donít water again until the pot has dried slightly. Water less in fall and winter.

You can find many, many varieties of standard Cymbidiums, most much gaudier than my own. However, many of the highly colored ones lack the beautiful scent and the great vigor of my variety, so Iím not collecting any more - Iím content to keep 2-3 pots of this one kind about. However, if you have the right conditions, the same three pots, split over 3 varieties with different blooming times (ask the grower!) would give you corsage flowers continuously from December through March.

Borderline Cool - Phalaenopsis

Most orchid growers would not include the genus Phalaenopsis amongst the cool growers. These are the fairly common "moth orchids" and many of them are best in a warm room. However, there are species in the wild which grow at higher elevations or further north, and hybrids descended from these can take fairly cool temperatures. I have two varieties, one of which doesnít appear to like our cool kitchen annex, the other of which is ready to bloom as I write this.

"Phals" as theyíre known to aficionados are actually easier for those in apartments or without sunny windows than the "Cyms" which like a bit brighter light. Most Phals will grow well in an east window or under fluorescent growing lights. Noonday and early afternoon sun should be avoided, except perhaps in midwinter. Rooms temperatures of 20-25įC in daytime and 5įC cooler at night are desirable. However, a period of cooler temperatures in fall can help start buds in some varieties. My plant probably can handle day temperatures of 16-18įC and night temperatures as low as 12-14įC, although this is probably as cool as it should get.

Phals are epiphytes - plants that grow way up in the air, on tree branches. Thus the potting mix must promote excellent drainage and lots of air to the roots, or theyíll quickly rot and die. The usual mix is something like bark chips, perhaps with a small amount of perlite added. Some growers use sphagnum moss or fern roots instead. Water every few days when the mix has dried out - too frequent watering will kill the plant! I use a very dilute orchid fertilizer in each watering, although Iíve read I should perhaps skip this in late summer and early fall.

Phals are smaller; typical plants will be in a 4" pot and the bloom stalk is about 4-6" high and a perhaps 6-12" long. A single bank of fluorescents would grow perhaps a dozen plants. The flowers are very long-lasting, 1-2 months when not cut, and 1-2 weeks when cut. Mine is pure white except for stripes of red on the central parts, but there is an enormous range of Phalaenopsis hybrids.

There are many good books on growing Phals, so I wonít go into all the details of their care. Borrow or buy one and read all about it!

Sinister Beauty - the Paphiopedilums

My last, and most finicky cool orchid is a Paphiopedilum hybrid. This genus is the tropical counterpart of our northern ladyís slipper orchids. Like the ladyís slippers, "Paphs" have a odd-looking "slipper" instead of the open lip of the Cyms and Phals. Also like the ladies, they tend to grow in more soil-like conditions on tropical forest floors, so can be less finicky about potting medium. Like Cyms and Phals, some Paph species come from highland forests, others from warm lowlands. The most reliable way to distinguish this ancestry in the hybrids is to look for clear green leaves in the highland descendants, and mottled leaves in the lowland types. A mottled-leaf Paph is striking even out of bloom, but it wonít like my cool windows in winter - donít buy it unless you have consistently mild growing conditions.

As forest floor types, Paphs tolerate and need quite a bit of shade. I leave mine in the dappled shade of the porch railing all summer long, tucked under the leaves of the Cyms where they wonít get sunburnt. I bring them inside about 3 weeks to a month earlier than the Cyms, usually late September. Inside they start off some distance from the south-facing window, then gradually move closer to it as winterís short, dim days arrive. By March they need to be moved again to an east or perhaps even a bright north-facing window, until they can be moved outside again in May.

Iím madly in love with these plants but seem not to have the knack. After several disasters I now plant mine in pure bark chips, which forces me to use the dilute orchid fertilizer (bark has few nutrients). Flower colors tend to have lots of spooky green-brown-black mixes. Some of the most desirable hybrids have black-striped lower petals (sepals, actually, but petals to you and me) with long tails. Unfortunately, these seem to be predominantly of lowland ancestry and are not for me.

We have friends in Vancouver who grow Paphs and Phals in a north-facing bay window with great success, proving that these groups are ideal for those without direct sun.

The clear-leaved Paph hybrids can tolerate conditions nearly as cool as the standard Cyms. Donít put them on a windowsill with a radiator or heating vent underneath!

You donít need a greenhouse!

I hope this brief overview has convinced you that there are orchids you can grow without a tropical greenhouse. Theyíre not too hard to care for if you study their needs a little, and they can give an awful lot of satisfaction when they do well!

 

Copyright 2001 by Clement Kent, c l e m e n t @ g o d e l . n e t

Articles