Why do orchid leaves turn yellow and the plant collapse?
1. In a pot of orchid plants, the outermost leaf of one plant gradually turns yellow from the tip, with a tendency to extend downward, and this can last one to two months or longer, eventually the whole leaf turns yellow and withers. This is a normal decline phenomenon of old plants, and this situation is commonly seen on old plants after two years of growth. Leaf tip...
If the leaf tip is scorched yellow and shows a slow downward trend, it may take up to a year before the decline of a single leaf ends, and this is also normal; but if leaf after leaf on the plant has scorched tips, then it belongs to damage to the orchid roots in the pot, and it should only be dealt with when repotting in a suitable season. This is mainly caused by compacted potting soil, poor air circulation, and improper water supply.
2. The outer bract leaves (protective leaves) of mature plants: if the orchid is growing normally, it can maintain the integrity of the whole plant. But commonly the outer bract leaves either wither and yellow or fall off, forming an abnormal state in which only the long leaves (that is, the leaves grown in one flush) remain to sustain growth. Anyone with even a little cultivation experience can tell at a glance that this is caused by poor cultivation and management. Generally speaking, incomplete bract leaves reflect that the surface soil in the pot is too shallow or the potting surface soil is too coarse, or that the water supply to the potting soil is insufficient, at least that the upper half of the potting soil is too dry, and that the roots related to the protective leaves have been damaged. Improvements for this problem are not restricted by season or weather; just deal with it promptly once you are sure of it.
3. Physical injury may also damage some leaves, and the consequences of injury are also varied. There are cases where leaf veins are blocked due to excessive pressure on the leaf, where half of the leaf is damaged and the pressed part gradually turns yellow; cases where only the leaf tip is bent and cannot recover, and the crease is too deep for growth to resume; cases where a leaf is torn from the middle, or damaged by strong wind beating on it for a long time, and so on. For these aspects, once discovered, just do local trimming, or change the position of the orchid pot.
4. Due to lack of common sense or carelessness, the orchid pot is placed under clothes hung out to dry after washing and receives many drips of laundry water. In about twenty to thirty days, all the orchid leaves in the pot turn yellow day by day, and finally the whole orchid plant dies. Although this situation is rare, there are still cases of it. Once this situation is discovered, immediately wash the orchid plant with plenty of clean water; in severe cases the potting soil must be discarded and the plant repotted; if discovered rather late and a large number of leaves have already turned yellow, then besides repotting with new soil, also cut off the leaves that have turned yellow to a deeper degree, and trim part of the root system, or choose soilless sphagnum moss for planting, taking care to keep it shaded for a period, adjust it slowly, and cultivate it carefully.
5. Improper watering: whether by spraying, irrigating, watering, soaking, or sprinkling, try to avoid water entering leaf buds and flower buds that have just opened. At this time, once too much water is received, plus poor ventilation, or too high or too low a temperature, it is most likely to cause bud rot. If you do not pay attention, at first glance the color of the upper half of the leaf bud has not changed, and you only feel that the leaf bud has not grown taller for a fairly long time; only on closer inspection do you find that the color inside the bud opening and in the lower half of the leaf bud has already changed slightly, commonly appearing brown. At this time, with just a light pull, the leaf bud whose base has already rotted will come up.
6. Because when planting orchids, too much base fertilizer was applied in the pot (including organic fertilizer or chemical fertilizer), in the short term the orchid plants look very vigorous, with oily green leaves and new shoots growing rapidly. But after the water is on the dry side, the whole pot of orchid plants gradually turns yellow, and even completely collapses; or orchid plants buried relatively deep in the clump develop blackening and rot starting from the heart of the plant. In most of these cases it is hard to remedy, and this is called fertilizer damage. If discovered early, the soil must be replaced, and the plant cared for slowly in a cool, ventilated place.
7. Because of excessive division and replanting of seedlings within a year, supposedly for loosening and easier propagation, the result is that it violates the characteristic of orchids having a clustered growth habit, and instead makes it difficult to produce new leaf buds and to bloom the following year; not considering seasonal factors within a year, repeatedly turning the soil and changing pots will likewise be unfavorable to normal growth and delay the settling-in period, and combined with poor management, it will also cause withering and collapse.
8. In ordinary cultivation and management, if in a family only one person takes care of things and others generally do not ask about them, then once this orchid lover is away on official business or for some reason and cannot take care of them for a time, the orchid plants are left to fate, and as a result collapse and death are hard to avoid. The way to improve this is not difficult: there must always be someone in the family to take over, and there must be no gap in the management chain, otherwise this orchid lover's hobby will be hard to sustain.
The various situations above show that there are many causes of orchid plant collapse and necrosis. In addition, rodent damage and bird damage are also headaches, but most factors harmful to the normal growth of orchid plants can mostly be avoided. The problem lies in careful observation in daily management, and taking action to solve a problem as soon as it appears. By no means wait until the plants have collapsed and the orchids have died before hurriedly trying to rescue them. You must know that in this path of growing orchids, impatience and carelessness are both harmful. Effort must be spent in ordinary times, so as to prevent trouble before it happens. In my own long-term practice, I have deeply realized that no matter what the cause, once the situation of orchid plant collapse appears, the trouble it brings is obvious. To restore vitality to the pseudobulbs after collapse, or what is ordinarily called the "false bulbs," is easier said than done. Not to mention the economic loss and the emotional setback, what is even more distressing is the waste of time, which is hard to bear. From taking the pseudobulbs after collapse and root rot to recultivate them, to the pseudobulbs sprouting again and growing roots, then to the plants becoming a full pot, and finally blooming, if everything goes smoothly it still takes 2-5 years; to rescue part of the collapsed plants and truly restore their vitality also takes 1-2 years. In short, this is what ordinary orchid growers least want to see or encounter. But when it happens, fear and anger are of no use; only by facing reality and dealing with it with a positive attitude can the orchid plants be saved from the brink of death. This is still a joy for orchid growers after achieving success and harvest, and it is worth every orchid lover's practice and experience of the sweetness and bitterness in growing orchids. This is likewise a process of learning and training, and also an unavoidable reality for the vast majority of orchid lovers.