Orchid Growing under Glass in Southern Ontario.

My aim in developing this website is to provide information and recommendations for those considering growing orchids under glass in Southern Ontario. Growers in other parts of Canada and the USA with different climates may have to modify these recommendations, but the basic approach should still apply. I have also listed reasons for my choice of a Solarium rather than a 'stand alone' Greenhouse.

Advantages of a 'lean-to' Solarium

My solarium measures about 18ft x 10ft and 9ft high at the house side, where a sliding glass door allows entry. A second sliding glass door gives access to the outside. All glass is double glazed for necessary insulation. Also the structure is made from aluminum channels with built in thermal barriers which prevent direct metal to metal contact between inside and outside.

It has 3 swing windows, 2 thermostatically controlled Expelair exhaust fans mounted high up for exhausting hot air in the summer, and 3 small inexpensive fans running constantly to provide further ventilation at all times. The flooring consists of cedar boards with a 1/2" gap to allow airflow from the basement via a shallow crawlspace. Another fan, controlled by a thermostat is mounted so that it can force basement air through a hole in the basement wall below the flooring. The resulting pressure in the solarium causes warm humid air to flow into the living room, providing some winter heating and needed humidification. In summer, cooler air from the basement helps evacuate hot air through open windows and the exhaust fans, with the door into the living room kept shut, so that the house in not heated unnecessarily.

A hot air duct from the house forced air heating system is set against the walls under the floor boards and a 4.5kw heater gives auxiliary heat when required. A commercial humidifying unit controlled by a humidistat maintains the humidity at about 40% min.

The plants are grown on wooden benches topped with egg crate louvers to allow free air movement from below. Plants are also suspended from overhead pipes which hang from the aluminum rafters.

Water is available via an extension pipe from the house plumbing and rain water is provided by a small pump in the basement where rain water is collected in 50gal drums. These recycled drums are made from heavy duty plastic and have been thoroughly cleaned. The incoming rain water is turned off by a float valve (used by farmers for water troughs) when the drums are full.

My Solarium faces South which is the best direction for maximum light. However, direct sunlight on a summer's day is much too strong for almost all orchids. Shading is required and in my case 60% shade cloth is used with an automatic roller system. This provides about 40% sunlight (4000 foot candles) on a sunny July day, which is on the high side and good ventilation is required to prevent burning. I would recommend 70% shade cloth which is safer. An automatic shade is not essential, especially if full sun is available all day. A static shade cloth is fine and whitewash is another method. The pictures show my solarium, inside and out. Note the plants sitting on benches and also hanging from overhead.

Now for some cultural information

The most popular types of orchids grown by hobbyists can be divided into several genus's

These include the very showy large corsage types called Cattleya; the charming lady slippers known as Paphiopedilums; and the so called 'Moth orchids' the real name being Phalaenopsis

In each case, appropriate light intensity, temperature and humidity is vital. I operate my solarium at an intermediate/warm temperature which means a minimum of 15C and a maximum not exceeding 30C if possible. Under these conditions I cannot expect to grow cool growing orchids such as most Odontoglossoms and Masdevalias, so I do not even try, beautiful as these plants are. If you want to grow cool growing orchids then you will not be able to succeed with warm growing types such as Phalaenopsis and Cattleyas, at least in a small solarium.

This picture also shows the extensive use of Spanish moss for providing shade for the lower light plants, such as Phalaenopsis and Paphiopedilums. Also can be seen the electric auxiliary heater under a small table and the humidifier above it. The moss is sprayed at the same times that I water unless the weather is dull when so much humidity in not required. In winter most of the Spanish moss is relocated against the vertical frame members to allow maximum light for all plants. By this time the moss has grown so much that I have to dispose of some of it. Spanish moss is actually a member of the Bromeliad family and is often found growing along with Orchids in the wild. It is an air plant having no roots and even has tiny white flowers. Instead of using Spanish Moss to provide more shade, shade cloth can be used of course in the form of curtains. However, installing it may be more difficult than just hanging Spanish Moss and it will not provide that extra humidification either.

For Cattleyas and their relatives, please click Cattleyas for more cultural information.

Blc.Pink Beauty

This picture is of a typical Cattleya hybrid, with 6" fragrant blooms. Cattleya blooms can measure up to 9" and colours range from pure white, pink, red, lilac and also multicoloured.

There are also minicatts; small plants with small blooms which are a good choice for window-sill growing.

For Paphiopedilums, species and hybrids, please click Paphiopedilums for cultural details


This picture shows a group of Paphiopedilum hybrids and species with 3" blooms. Colours include white, pink, reds and greens and some are striped or spotted. Shapes can also vary considerably.

For Phalaenopsis, species and hybrids, please click
Phalaenopsis for cultural information.

The picture is of a pink Phalaenopsis hybrid, but other colours include pure white, red, yellow and combinations of colours with spotting, stripes and various combinations of these.

There are many other orchids which belong to different genus's and I list some of these which I have grown and present them all together. Please click 
Other types.

Please remember, this cultural information is only an approximate guide and one needs to obtain more detailed information for a specific plant, using books or the internet. An even better source for cultural information is to belong to an Orchid Society, where you will meet members with a wide range of Orchid growing experience and also a source for low cost plants. Also each growers conditions will be slightly different and so fine tuning is required. This can only be achieved through experience, so start small and as experience is gained, the Orchid collection can be expanded.

Here is my E-Mail address if you would like to make contact : j.follen@sympatico.ca

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