Greenhouse Gardening – orchids

Orchids belong to the most diverse family of plants known to man. There are over 880 genera, 28,000 species and well over 300,000 registered cultivars currently documented. These numbers only begin to tell the true story behind the evolutionary success of modern day orchids. Orchids are the most rapidly changing group of plants on earth in genetic terms and more new species have been discovered over the last few thousand years than any other plant group known. One reason for this surge in discovery is our desire to own and grow orchids, and this is easy to do in a specially managed area of the greenhouse.

They are plants that prefer about 60% humidity. Ideally, set your orchid pots on pebbles in a water-filled tray because the water evaporating from the large surface area provided by the pebbles increased the humidity. Pebbles also make the growing area more attractive, while assuring good drainage. Mist your plants with distilled water because tap water can lead to salt deposits on the leaves. A plant which is kept soaking wet will be the victim of either bacterial or fungal diseases.

Temperature can vary:

Cool orchids include Cymbidiums, Cypripediums, Odontoglossums and Miltonias, and should be grown 5 degrees to 10 degrees F cooler than the medium class. These plants also require high light, so imagine cool, sunny October mornings as an example of the light and temperature they really enjoy.

The medium temperature class is represented by many Cattleyas, Epidendrums, Oncidiums, and Laelias, and most other commercially available orchids. The ideal minimum temperature is 60 degrees F at night and something in the high 70s during the days but the occasional variation won’t have any harmful effect.

Warm class orchids are represented by Phalaenopsis, Paphiopedilums, Vandas, Rhynchostylus and Dendrohiums. These plants should be grown 5 degrees F warmer than those in the medium and they love a high humidity.

Greenhouse gardening orchid photograph by –Lori- , used under a creative commons attribution licence