What's the Deal with Black Spots on Phalaenopsis? A Breakdown of Bacterial and Viral Infection Types
On the journey of growing Phalaenopsis for the first time, you're bound to run into plenty of novel problems, such as leaves suddenly turning yellow, leaves drying up, or even leaves suddenly developing "dark black spots." Generally speaking, this kind of condition is usually caused by bacterial or fungal infection. Although it sounds quite serious, as long as we can promptly spot and deal with the early signs of black rot, there's a chance of saving the whole plant. Let's take a look together.
In fact, all sorts of leaf problems are not limited by season. They can happen in winter, because it's cold outside and everyone keeps doors and windows shut tight, which can lead to poor ventilation and infection. They can also happen in summer, when even with good ventilation, the high-temperature environment can cause Phalaenopsis leaves to become infected with spot disease, also known as "black rot." All in all, black rot in Phalaenopsis is as common as a cold in humans. So we need to check our plants often, especially the surface, the underside and the gaps between the leaves. Usually, you just need to gently press the leaf with your hand; if the leaf feels soft and rotten, that may be a sign of black rot.
In addition, besides "black rot" there is also "water rot." The main difference between the two lies in how the leaves change. Black rot makes the leaves turn black, while water rot makes them soft and translucent. As for how to handle these two conditions, they usually occur mainly on the leaves and not on the roots. Once you spot the condition, you should take action immediately. When cutting away diseased leaves, remember not to cut only halfway; the entire infected part should be removed completely. After handling it, you can dust the cut with dry carbendazim powder, cinnamon powder, plant ash and the like to help the wound heal.
Finally, once it's been handled, just put the plant back where it was. At the same time, please be sure to clean the scissors you used before; if the scissors have been used repeatedly, it's best to wipe them thoroughly with alcohol and let them dry to prevent any remaining pathogens. That way, the next time you use them, you'll avoid spreading pathogens to other parts.