Among these, some argue that they should never be pruned because of their spontaneous renewal after the withering of the flowers; someone else believes that it is always better to prune, removing - in addition to the withered flowers - even the old stems, so as to favor the complete renewal of the plant and consequently a better flowering. For the pruning of orchids it is also necessary to consider the cultivated variety. Some, after having dried the previous stem, produce new stems; others always bloom on the same. Furthermore, certain orchid varieties spontaneously vary the flowering of their stem and according to some, it is preferable to let the plant renew its stems in a natural way, following its own growth rates. Generally, however, apartment orchids, those cultivated in pots, are pruned: dendrobiums, originating in New Zealand and with the ability to spontaneously wither the now unproductive stem, and phalaenopsis originating in the Indies, with the property of renewing the stem independently. In both cases, pruning will be performed by simply removing the withered flowers.
However, there are some species of orchids that benefit from the complete removal of the stem because they bloom on a new stem. These include Cambria and Cymbodium.
The pruning of orchids although it can serve to give vigor to the plant, has essentially an aesthetic goal and could not be otherwise since this type of plant has above all an ornamental purpose.
In any case, you will not be mistaken when you prune your orchid when it gives visible signs of suffering: dry, broken or withered branches.
There are two pruning techniques: the complete removal of the withered leaves and flowers or the cutting of the stems of the now unproductive plant. As for the removal of the flowers, it is advisable to cut them from the peduncle. Instead, with regard to the stems, many gardening enthusiasts choose to prune even the productive branches, this to force flowering, about 20 cm from the base, immediately after the node from where the new stems should originate.
Others prefer to cut the stems in their terminal part. This procedure is useful for those orchids that produce the second flowering on a new stem.
The tools to be used for pruning are gloves and special scissors, washed and disinfected both before and after use. The cuts to the stems must be decisive since creating frays to the plant tissue - even with a minimum of hesitation - promotes the penetration of pathogens into the plant. The cuts must then be protected with putty to prevent viruses and bacteria from causing infections.
As far as leaves are concerned, it is better to let nature take its course. Orchid leaves generally fall off on their own after a long period of 2-3 years. They are in fact a water storage organ and should not be cut, unless they show evident signs of disease or rot.