Cymbidiums

There are few places in South Africa where cymbidiums won’t grow – they are tough and can handle fair amounts of cold, even with some light frost. The plants can even handle hot summers. It was always thought that cymbidiums couldn’t be grown and flower along South Africa’s east coast, but with careful selection you can find a few cymbidiums that will even flower in places like Richards Bay.

Cymbidium plants have oval to rounded pseudobulbs that sit just above the substrate, and long grass-like leaves that arch towards the tip. The flowers come in a range of different sizes and may be carried on upright, arching or even pendant stems. In general, the miniature and intermediate type of cymbidium hybrids are the first ones to start flowering during autumn. The biggest group of cymbidiums tend to flower during winter, and in spring the large-flowered hybrids as well as the pendulous types start flowering. Cymbidiums are popular as pot plants as well as for the use in the cut-flower trade, and the long-lasting flowers will keep just as long if cut and placed in water in the home as they would on the plant.

Cymbidiums are very rewarding and in many cases flower with great consistency even with a lot of neglect and sub- optimal growing conditions. If you treat your cymbidiums a little better, though, you will just have so much more reward.

What conditions do cymbidiums prefer?

• Bright light. A few hours of direct morning light followed by some dappled light in the garden is best. If you grow your plants in a shade house they should preferably be grown under 50 – 60% shade. Don’t try and grow your cymbidium as an indoor houseplant – it will never flower.
• Potting medium that drains well, but still maintain some moisture around the roots. These plants do thrive if kept fairly moist during the growing season.
• Regular feeding during the growing season will ensure lovely plump pseudobulbs, and therefore good flowering.
• Most cymbidiums require a difference of about 10°C between the day
  and night temperatures while the inflorescences are initiated (usually January or February). If the plants are placed on paving or directly adjacent to a stone/concrete wall this will be difficult to achieve with the residual heat that has been built up during the day and is given off during the night.
• Good air movement is vital. This will not only help with the temperature difference to initiate flowering, but will also help prevent pests and diseases. Avoid putting your cymbidium plants in a corner or placing them too close together – allow for some air movement between plants.

If you choose your plants right, you could have cymbidiums in flower all the way from April until October (with the odd species and hybrid even flowering in summer). So the next time you see a yellow cymbidium flowering in May, don’t say, “Oh, that’s flowering early. Mine usually flowers in September!” Instead appreciate that it is a different plant, and you could also have one flowering in May as well and so lengthen your season of cymbidium enjoyment.

Read more about orchids in the July 2020 issue of The Gardener and Die Tuinier. Find a store near you or read it online.