Orchid disease prevention and treatment methods, for the reference of orchid growers

     

        1. In a pot of orchid plants, the outermost leaf of a particular plant gradually turns yellow starting from the tip, with a tendency to extend downward, and this may take one to two months or even longer, eventually the whole leaf turns yellow and withers. This is the normal decline of old pseudobulbs, and this situation is commonly seen on old pseudobulbs that are more than two years old.

The leaf tip scorches yellow and tends to extend slowly downward, and it may take up to a year before the decline of a single leaf ends, which is also normal; but if every leaf on the plant has scorched tips, then it is due to damage to the orchid roots in the pot, and treatment should only be carried out when repotting in a suitable season. It is mainly caused by compacted potting soil, poor air circulation, and improper water supply.

2. The outer bract leaves (protective leaves) of a mature plant, if growing normally,orchidcan maintain the integrity of the whole plant. But the outer bract leaves commonly either wither and yellow or fall off, resulting in an abnormal state where only the long leaves (i.e. the leaves that grew out in one season) remain to sustain growth. Anyone with even a littlecultivationexperience can tell at a glance that this is caused bycultivationand poor management. Generally speaking, incomplete bract leaves reflect that the surface soil in the pot is too shallow, or the soil on the pot surface is too coarse, or the water supply to the potting soil is insufficient, at least the upper half of the potting soil is too dry, and the roots related to the protective leaves are damaged. Improvement of this problem is not subject to the influence of season or weather; just handle it promptly once you are sure of the diagnosis.

3. Physical injury may also cause damage to some leaves, and the consequences of injury are also varied. There are cases where the leaf veins are blocked due to excessive pressure on the leaf, or half of the leaf is damaged and the compressed part gradually turns yellow; there are cases where only the leaf tip is bent and cannot recover, and the crease is too deep for growth to resume; there are cases where a leaf is torn apart from the middle, or damaged by being battered by strong wind over a long period, and so on. For these situations, once discovered, just carry out local trimming, or change the position of the orchid pot.

4. Due to lack of common sense or inattention, the orchid pot is placed under clothes hung out to dry after washing, receiving a lot of dripping laundry water, and within about twenty to thirty days, all the orchid leaves in the pot turn yellow day by day, finally causing all the orchid plants to die. Although this situation is rare, there are not a few such cases. Once this situation is discovered, immediately wash the orchid plants with plenty of clean water; in severe cases the potting soil must be discarded and the plants repotted; if discovered relatively late and a large number of leaves have already turned yellow, then in addition to 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 to plant in soilless sphagnum moss, taking care to shade it for a period, adjusting it slowly and cultivating it carefully.

5. Improper watering, whether by spraying, flooding, pouring, soaking or sprinkling, should 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 excessively high or low temperatures, it is most likely to cause bud rot. If you do not pay attention, at first glance the upper part of the leaf bud shows no colour change, and you only feel that the leaf bud has not grown taller for a relatively long time; only on closer inspection do you find that the colour inside the bud opening and in the lower half of the leaf bud has already changed slightly, commonly appearing brownish; at this point, with just a gentle pull, the leaf bud whose base has already rotted will be pulled out.

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 appear to grow very vigorously, with oily green leaves and new shoots growing rapidly. But after the water becomes somewhat dry, the whole pot of orchid plants gradually turns yellow, even to the point of complete collapse; or orchid plants buried relatively deep in the clump develop blackening and rotting starting from the centre of the shoot. This kind of situation is mostly difficult to remedy, and this is called fertilizer damage. If discovered early, the soil must be replaced, and the plants tended slowly in a cool, ventilated place.

7. Because of excessive division and replanting of seedlings within a year, ostensibly for looseness and easy propagation, the result is that it goes against the characteristic of orchids as a family with a clustering growth habit, and instead makes it difficult to produce new leaf buds and affects flowering the following year; not considering seasonal factors and repeatedly turning the soil and changing pots multiple times in a year will likewise be detrimental to normal growth and delay the settling-in period, and combined with poor management, will likewise cause withering and collapse.

8. In ordinary cultivation and management, if in a family only one person takes care of things and the others generally do not ask about it, then once this orchid lover is away on business or for other reasons and cannot tend to them for a time, the orchid plants are simply left to fate, and 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 gaps 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, damage by rats and birds is also a headache, but most of the factors harmful to the normal growth of orchid plants can be avoided by one means or another. The problem lies in careful observation in daily management, and taking action to solve a problem as soon as it arises. Never wait until the plants have collapsed and the orchids have died before rushing to rescue them. One must know that inorchid growingthis pursuit, impatience and carelessness are both harmful. Effort must be spent in ordinary times in order to prevent trouble before it occurs. In my own long-term practice I have deeply realised that no matter what the cause, once the situation of orchid plant collapse appears, the trouble it brings is obvious. To make the pseudobulbs after collapse, or what is commonly called the “pseudobulb”, recover their vitality 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 plant becoming a full pot, and finally flowering, if everything goes smoothly it still takes 2——5 years: to rescue part of a collapsed plant and truly restore its vitality also takes 1—2 years. In short, it is what ordinaryorchid growersmost do not wish to see or encounter. But when it comes, fear and anger are of no use; the only way is to face reality and deal with it with a positive attitude. To be able to save orchid plants from the brink of death is still a case oforchid growersenjoying the joy after achieving success and harvest. It is worth every orchid lover practising and experiencing the sweetness and bitterness of orchid growing. This is likewise a process of learning and training, and it is also an unavoidable reality for the vast majority of orchid lovers.