Cymbidium( SIM-BID-EE-UM) are easy to grow and readily available but the majority do get large so bear this in mind when choosing plants. The ones we normally readily see are standard Cymbidium hybrids which produce large spikes and big clumps of large bulbs. I have one that takes up about 900mm square of bench space and is now getting to a point where I don’t know what I will do with it next.
You can get more delicate species of which there are about 50, they are found in China, Japan, South East Asia to Australia. They may be epiphytic, terrestrial or lithophytic- growing on rocks. These are more difficult to cultivate so not the choice if you haven’t researched their natural growing conditions.
Cymbidiums are mostly cool growing, there are some warmer growing species. Mine are kept in the 5c winter minimum half of the greenhouse and have never failed to flower well. They need these cool temperatures to flower well and if kept in a warm heated home can prevent the plant from flowering. So a unheated room would be best if you have them in the home, they may grow great but may never flower if kept warm!
They are heavy feeders but I don’t give them any more feed or at a higher strength than my normal feeding regime, so it is kept simple no bloom or boost feeds for me; see my feeding article. They do get a few doses of Epsom salts( up to table spoon per 10 litres) in the growing season and a supplement of dolomite lime where I sprinkle it over the surface of the potting mix where it will wash in. The dolomite lime is applied late in the growing season(late summer) and contains Potassium and Magnesium. Some species are not lime tolerant and are acid loving so bear this in mind when thinking of applying lime.
They get a foliar feed and mist most days in summer and are watered when the potting mix becomes slightly dry, not dry. When the risk of frost has passed they can go outside shaded from the sun, very early morning summer sun and late evening should be fine.
Mine stop in the greenhouse but when I did have them outside I liked to have them under cover so I controlled watering and to prevent excessive rain rotting any new growths. One year this did happen, it was a wet late spring and this rotted a lot of growths so hear the warning! After this bad experience I put them outside in the open but under cover.
When they get large they leave bare bulbs in the centre of the clump and the only option when the plant becomes untidy is to divide. This is easy to do and best to do in spring just before the new growths get going. Usually you can see where to divide a plant, divide in to good sizes at least three bulbs, any single bulbs can be potted up where they will produce a growth and become a new plant!
They have thick roots so a chunky potting mix works well, I have used all sorts of mixes and they usually get what ever I have left over!
A good starting point with potting mix would be medium or large bark, sphagnum moss and perlite or sponge rock at a ratio of 3-1-1 ;you can play about with the ratio of the mix to suit your growing conditions. Putting your potting mix on a tray and feeling it by squeezing in your hands gives you a good idea of what you want.