Are withered orchid leaves a disease? A full analysis of how to tell

Orchid growers all want their orchid leaves to be dark green and upright, but in reality we often run into leaves that turn yellow or black. So, is the withered orchid leaf the questioner asks about a disease? Is it necessary to apply pesticide? In this article I will not discuss blackened leaves, but only the withered leaves the questioner asks about...

Withered orchid leaves usually fall into three situations. Let us analyze them one by one, and you will understand whether it is a disease.

1. When a wild-collected orchid (xiashan orchid) is newly potted, the orchid needs a period of acclimatization to the pot. During this time the orchid roots do not produce new roots, and they also need time to adapt to the new planting environment and potting medium. The orchid roots cannot draw nutrients from the soil, yet the orchid plant will not stop growing for this reason, so it must take nutrients from the old growths, causing the old growths to turn yellow and wither. This is normal shedding of old growths, not a disease, and it will be fine once the orchid has acclimatized to the pot.

2. The potting medium or environment is too dry, causing the orchid roots to lack water. The plant's instinct to reproduce will ensure nutrients for the new growths, so the old growths will supply them without compensation, and this is also a cause of orchid leaves turning yellow and withering. Observe carefully whether it is lack of water. At this time do not water heavily, because the orchid roots are too thirsty and cannot drink too much water at once; it is better to water lightly and frequently to help the plant recover.

3. Disease. The symptoms of diseases caused by many pathogens include withered leaves. After ruling out the above two causes, it is basically this third one. Only this kind of withered leaf requires pesticide application, mostly fungicidal medications, and the growing position should be moved to a cool, ventilated place. Once orchid leaves have withered, it is irreversible. Regardless of which situation it is, in the end the withered leaves must be cut off.