Some of the easiest and most rewarding plants in my garden are the Cymbidium orchids. I give them very little attention and in return they provide a long-lasting and spectacular show of exotic blooms from mid-autumn through to the end of winter. Cymbidiums develop from a false bulb, called a pseudobulb. Vegetative shoots (leads) arise from the base of this pseudobulb, as do flower spikes. After several years, the leaves break off and the bulb becomes a backbulb, which continues to provide nutrients to the new growth until it withers and dies.
As Cymbidiums are usually found in nature growing as semi-terrestrials or even an epiphyte (a tree-dwelling plant) their specially adapted and long-lived roots are covered in a thick layer of absorptive tissue called velamen, which helps absorb water and nutrients from the surrounding environment. In the garden, Cymbidiums are largely pest and disease free, with the main issue being slugs and snails that chew the flower stems and new flower buds as they emerge. Regular application of slug pellets starting early April is usually enough to fix this issue.
In warm temperate regions such as ours, Cymbidiums will do just fine in the open garden, if they have a little shade during the hottest part of the day and protection from frost in winter. An overhanging tree, palm or punga is ideal and a light-green leaf colour indicates the plant is getting sufficient light intensity for good flowering. Cymbidiums prefer regular watering during spring and summer when they produce their vegetative growth, but if water is in short supply, they will survive better than most other garden plants. Feeding with diluted liquid fertiliser, sheep pellets or slow-release fertilisers from spring to mid-summer is beneficial, but again, if you forget the plants will just hang in there!
Cymbidium do need very free draining and slightly acidic potting mix with large air spaces for healthy roots. Mixes containing coarse coir fibre or bark chips are typically used for potted plants. I place my potted orchids in the background of the garden from spring, then bring them forward in late summer to keep an eye on the tender flower spikes and to highlight their blooms. Commercial growers use strings to keep the stems straight, but I prefer the arching look.
Planting the Cymbidium in the crook of a tree or on an old punga is another really good way of showing off these plants, to take advantage both of their epiphytic nature and the lovely show of blooms cascading downwards. Cymbidiums can also be permanently planted on the soil, using a mound of bark mulch and other fibrous material to hold the roots out of the soil itself.
Potted Cymbidiums are usually divided and repotted into new mix every two to three years during summer. Miniature hybrids often do well for five or six years before needing division. Plants are removed from their pots and split into a few decent clumps using a sharp knife or hand saw. Backbulbs are usually left on the division to add strength to the new growth. And that is about all you need to do to enjoy these glorious flowers every year.