A monthly growers advice column by Courtney Hackney. Hackneau@comcast.net
“Do no harm” is a basic tenant of the medical profession that many orchid hobbyists would be wise to adopt. A large number of orchids I see in my travels suffered premature deaths or injury, largely because of a misinformed attempt to help the orchid grow. The following is a list assembled from my experience with other growers and from my own mistakes.
“My orchids get the best water money can buy.” My first question of the novice holding a shriveled, dead orchid is about their water. One person even admitted that she had a water softener installed for her orchid because she knew her water was “hard”. Hard or mineral laden water may not be ideal, but softened water introduces salts that are toxic to orchids and typically lethal within a few weeks.
Another common mistake is to over-fertilize based on the conclusion that a poorly growing orchid needs more fertilizer. If over-watering is the number one killer of orchid plants, over fertilizing is number two. Fertilizers are nutrient salts that plants require along with water and light to grow. Recently purchased orchid that have a good root system do not require much in the way of fertilizer. Often, these plants have been grown quickly in commercial nurseries by maximizing light, water, and fertilizer. In the home environment, light is typically limiting and the medium contains all the nutrients the orchid needs in the short term. More often, the orchid pot needs to be flushed thoroughly with water occasionally to remove nutrients and to keep roots healthy.
Some pesticide and fungicide warning labels seem to state the obvious, e.g. “do not drink this product”. Who would do such a thing? After fielding questions about pests, pesticides and orchids, I realize that no warning is too simple. Read the warning label carefully for both your own safety and the health of your orchids. The most common orchid-related pest problem seems to be overdosing and under dosing with pesticides. If the label calls for one teaspoon per gallon, use exactly that amount. Just because a scale infestation was “really bad” does not mean the concentration should be higher unless the label tells you to use a higher dosage. Some of the hormonal pesticides do prescribe lower concentrations after an initial treatment.
Another sometimes fatal error orchid hobbyists make is to change growing media because they see well grown orchids in some new medium. This often happens to relatively new hobbyists after purchasing plants from a commercial nursery or a visiting speaker. The mistake is to immediately repot every orchid into this “new medium”. In most cases, the results are disastrous. There is much to learn by examining the growing medium of a commercial grower or very successful amateur. But remember that their success is specific to a set of growing conditions that may be very different from yours. In some cases, plants growing poorly at commercial nurseries are discarded, leaving the impression that all orchids grow well in this new medium. Some groups of orchids grow well in one medium, but not in another.
There is nothing wrong with experimenting with a medium and evaluating how well your plants grow in that medium, but avoid a wholesale conversion to a new medium.
The most surprised individual is the novice grower that brings their plant in and asks what they should do to their orchid. Typically, their “problem” orchid has outgrown the pot, has roots going everywhere, and shows signs of having bloomed repeatedly. There is also usually an admission by the grower that they have neglected this “poor” orchid, but are determined to take better care of it next year. In other words, they have “done no harm” and the orchid has thrived.