What causes orchids to wither and die in winter?

Orchidsare in a dormant or semi-dormant state in winter. If cared for improperly, they are prone to physiological disorders; in mild cases the leaves turn yellow and withered but can still sprout again in spring, while in severe cases the plants may die. The causes are:

1. Potting soil too dry or too wet: Although orchids should have their water greatly reduced in winter, they cannot go unwatered, and the potting soil should not be allowed to dry out completely before watering. If the potting soil is too dry, and combined with the dry winter climate, the pseudobulbs are prone to shriveling and other tissues suffer from excessive water loss that affects metabolism, so the plant grows poorly, with leaf withering in mild cases and death in severe cases. In winter, orchids most dread waterlogged potting soil; too much water and poor soil aeration easily cause root rot and death.

2. Unsuitable water and soil: For watering orchids, rainwater or river water is best. If well water or fresh tap water is used, the potting soil tends to become alkaline, the soil quality deteriorates, the potting soil cakes, drainage is poor, and aeration is poor, all of which make the potting soil prone to staying on the wet side in winter and make root rot more likely. Therefore, the potting soil for orchids should be a loose, acidic soil, with a pH between 5 and 6.5 being suitable.

3. Improper watering method. In other seasons, orchids should be watered in the morning or evening, but in winter it is better to water at noon in sunlight, and after watering the plant should be placed in the sun for 1-2 hours, then moved indoors once the water at the base of the leaf cluster has dried. If watering is done indoors, water easily collects at the base of the leaf stems, making them too wet and causing the pseudobulbs to rot and the plant to die. Because different orchid varieties need different amounts of water, watering in winter should be handled differently. For example, autumn orchids should be watered thoroughly before the onset of winter, whilespring orchids (Cymbidium goeringii)should be kept moist rather than soaked through; during Major Snow, autumn orchids do not need watering, whilespring orchids (Cymbidium goeringii)are best kept moist; from Winter Solstice to Minor Snow, autumn orchids andspring orchids (Cymbidium goeringii)may go unwatered, or be kept to a level of eight parts dry and two parts moist.

4. Improper pot choice:For cultivatingorchids, clay pots are best. Clay pots have better aeration than glazed pots, drain water quickly, and the potting soil dries quickly too, which is very suitable for orchid growth and makes it less likely for the soil to stay wet for a long time, sopests and diseasesare also fewer. With glazed pots, however, especially in winter, root rot is often likely because the potting soil stays too wet.

In addition, orchids must absolutely not be fertilized in winter; winter fertilization most easily causes orchid root rot. The indoor temperature and humidity in winter should not be too high or too low, otherwise the plant will also grow poorly. Coal smoke should also be avoided, and when the room temperature is high, doors and windows should be opened for proper ventilation; when the temperature is too low, take care to protect against cold and freezing. Only in this way can orchids overwinter safely and not wither and die.