What are the precautions for fertilizing orchids in winter?

OrchidsGenerally no fertilizing in winter, but givenorchidsthe limitations of pot cultivation, and to achieve a certain purpose, targeted fertilizing is possible. 1. For orchid plants that have not been repotted for years, a light application of a compound fertilizer with a relatively balanced three elements N, P and K may be given, preferably at low concentration. 2. To increaseorchids' cold resistance, foliar spray of 1500 times potassium dihydrogen phosphate may be applied, spraying once every twenty days, choosing a windless sunny day, and keeping the air flowing well after spraying. 3. For orchid plants without flower buds and weak, small orchid plants, a single light application of low-concentration nitrogen fertilizer may be given. 4. Orchid plants that have already been infected by pathogens, have severely damaged root systems, or have not yet adjusted to the pot should not be fertilized. Regarding disease prevention and control, insist on prevention first, comprehensive management, and treating early, treating small, treating thoroughly. 1. Keep the environment clean, remove pathogen sources, adjust air humidity in good time, and ensure good ventilation conditions. This is a powerful measure to preventorchid grassfrom pathogen infection. 2. Spray pesticides regularly for prevention. Before the start of winter, spray once with carbendazim, thiophanate-methyl, and medical chloramphenicol 1000 times solution, then spray again after ten days or half a month. For preventive medication, it is recommended not to use Bordeaux mixture, so as to avoid clogging leaf stomata and copper poisoning. 3. Check the leaves regularly, and correctly distinguish pathogenic diseases from physiological diseases. For pathogenic diseases, the diseased spot tissue should be cut away as much as possible; for multiple sites and large-area infection on a leaf, that leaf should be removed and burned, and then medicinal spraying carried out; for variegated-leaf orchids with higher ornamental value, the needle-prick heat conduction method may be used for treatment, and then medicinal spraying carried out (see the note for the needle-prick heat conduction method). Regarding heat preservation and frost protection. Because the soil layer of potted orchids is single in structure, they do not have the geothermal heat of the deep soil of wild orchids, nor the heat released by the rich humus layer and microbial action of the surface soil, and even less the microclimate formed by mountain forests. When the temperature is below zero degrees, frost damage will occur. Rice straw covering, building a simple greenhouse, and moving them indoors may be used, while receiving full light. Control the temperature above zero degrees, with around ten degrees being best, so as to ensure the orchid plants have a good vernalization period without breaking their normal dormancy. Orchidwintercultivationmanagement is a topic with a very broad scope. Simply saying how to water, fertilize, and prevent disease in winter is inappropriate. Because the factors affecting the normal physiological activities of orchids are intricate and complex, and they are both interconnected and mutually restrictive. For example, the permeability of the growing medium determines the amount of watering, and the amount of watering in turn affects root growth, and so on. How can these factors be kept in a dynamic balance? This requires everyone, when cultivating orchidgrass, to comprehensively consider factors from all aspects, and especially to adopt corresponding measures according to one's own specific situation in growingflowers(such as local climate, potting soil and growing medium, environment, etc.). Wishing everyone success in growingorchid grass. Note: The needle-prick heat conduction method for treating diseases. This method was summarized by the author through practice, inspired byorchid-growingexpert Teacher Xu Dongsheng's use of a cigarette to burn diseased spots. It has the advantages of quickly killing (cauterizing) pathogens, being safe and harmless, and making small wounds, and is especially suitable for foliage plants. The needle-prick heat conduction method is divided into two methods: cold needle plus heating needle pricking, and hot needle pricking. The so-called cold needle plus heating needle pricking means first taking a metal needle (according to the size of the diseased spot and the thickness of the leaf, choose the thickness and material of the needle), disinfecting it with alcohol, and pricking it perpendicularly into the center of the diseased spot on the leaf surface. Use a burning flame (such as a lighter or candle) to heat the other end of the needle, so that the heat is conducted along the needle to the area around the diseased spot, thereby scalding the pathogens to death. The hot needle pricking method is to first heat an already disinfected needle with a flame to a certain temperature, then quickly prick it perpendicularly into the center of the diseased spot on the leaf surface. The former is suitable for infection with relatively large diseased spots, and the latter is suitable for relatively small diseased spots. In addition, whether using the cold needle method or the hot needle method, needles of different materials have different thermal conductivity, and needles of different thicknesses also conduct heat at different speeds. Interested orchid friends may first do a test on orchid leaves of the same thickness, determine the flame size and heating time, and then begin the actual treatment. The cauterized area is best slightly larger than the diseased spot. (Bao Dongping)