The title question can be taken in two ways. The first, stressing the “really”, is an accusation or at least a questioning of your sanity or intelligence. While that may be appropriate in some situations (and I’m certainly one likely to ask), in this piece, the question is intended to make one question if “what they are doing” really has the outcome they are expecting. In the world of orchid growing, evaluating our actions can lead to a great many examples where the answer is a pretty firm “no”.
A great example is disinfecting ex-flask seedlings before potting them up. Why? In-vitro culture is inherently sterile, so application of a fungicide or disinfectant treats nothing, imparts no “immunity” going forward and may negatively affect the plants. If you want to give those seedlings every opportunity, consider the application of a good probiotic like Inocucor Garden Solution instead, which can prevent future infections by pathogens.
Another example is misting orchid leaves to boost the humidity. Humidity, by definition, is “water vapor in the air”, not “wet leaves”. Water on leaves does not evaporate readily, orchids are poor at foliar absorption of water, and pockets of water sitting on the plant make great little incubators for bacteria and fungi.
A third is the use of the wrong pesticide. There is no use applying an insecticide to a mite infestation, for example. Mites are not insects. Likewise, the use of a disinfectant is of no value when dealing with insects or mites. Match the weapon to the prey.
Those are examples of actions that are more a waste of time and maybe money than anything else, but there is a common one that is potentially quite harmful – incomplete pesticide treatments. It is common for folks who have identified a pest to treat their plants once and assume they’ve gotten them all, especially when using systemic or translaminar pesticides. Unfortunately, that’s not the case at all.
First, we must recognize that pest infestations likely involve eggs, larvae and adults, and that most pesticides only kill adults of the targeted species. When we treat a plant, it is likely that our pesticide won’t kill 100% of the adults, allowing the survivors to reproduce and carry on the infestation, adding to the other eggs and immature “critters” that were not affected. Considering the rapid reproduction and maturation rates of most pests, it is usually a good idea to perform complete treatments a total of three times at one-week intervals, greatly increasing the odds of eradicating the entire infestation.
So, the conclusion/recommendation is that we had better take a moment to evaluate our actions before doing something, rather than relying on “collective knowledge” (“myths” or “old wives’ tales”) at face value. This website is dedicated to answering that very question, so please feel free to browse!