Analysis of the Causes of Dead Orchid Seedlings in Chinese Cymbidiums and Prevention Methods

Orchid seedlings develop scorched tips, yellow leaves, yellow leaf sheaths, rotten hearts, rotten roots, and rotten pseudobulbs, and eventually the entire plant dies, causing huge economic losses to investors in fine Chinese cymbidium varieties. Orchid enthusiasts have different opinions, and only when cultivation becomes difficult does one truly understand orchids. Investigation and analysis show the main causes:

First, excessive fertilizer. Chinese cymbidium cultivation media should be lean rather than rich; when mixing, do not worry that fertility is insufficient and add too much fertilizer-heavy medium. If the growing soil is found to be too rich, it should be replaced promptly or technically treated. During Chinese cymbidium management, if the plants can grow normally relying on the medium, there is no need for extra fertilization. When fertilization is truly needed, organic fertilizer should be the main type. Organic fertilizer must be fully decomposed before use; undecomposed grass material, bone meal, oil cake, etc. must not be used directly to fertilize orchids. Special orchid nutrient solutions are usually also a kind of fertilizer, and fertilizer damage from excessive application must be prevented. When using organic fertilizer or chemical fertilizer, it must never be too concentrated; dilute fertilizer applied frequently is essential.

Second, excessive pesticide use. Any medicine has side effects, just as a healthy person who takes medicine every day will develop problems even without illness. Commonly used medicines in Chinese cymbidium management can be divided by purpose into sterilizing agents, insecticides, and hormone agents. Frequent use or excessive doses of different medicines can all cause phytotoxicity. Prevention first, nip problems in the bud: healthy, robust Chinese cymbidiums can go without medicine, and only when pests or diseases truly require it should medicine be used in appropriate amounts. When temperature rises and humidity decreases, prevent normally dosed medicines and fertilizers from naturally becoming more concentrated and harming the seedlings.

Third, excessively high temperature. Chinese cymbidiums need to grow in suitable temperature and temperature-difference conditions. The suitable temperature for Chinese cymbidium growth is 15 to 30 degrees, and the suitable day-night temperature difference is 5-15 degrees. When the potting soil temperature is above 35 degrees, the day-night temperature difference is extremely small, or ultraviolet lamps shine for a long time, the plant vessels that transport nutrients for orchid growth are highly prone to mechanical damage, viruses and bacteria in the environment multiply extremely quickly, and Chinese cymbidiums are easily infected by viruses and bacteria, resulting in dead seedlings.

Fourth, excessively high humidity. The Chinese cymbidium growing environment should be dry rather than wet. Do not water too frequently, or pour overhead water during hot, high-humidity summer seasons, to prevent waterlogging from damaging roots and rotting hearts and causing dead seedlings.

Fifth, insufficient air permeability. Both orchid pots and orchid rooms need ventilation. Cultivation media should be coarse rather than fine. Orchid rooms dislike stagnation, so attention must be paid to ventilation. Do not let oily smoke discharged from kitchens or factories enter the orchid room; harmful gases breed viruses and bacteria and easily cause orchids to become diseased.

Sixth, dividing too thinly. Chinese cymbidiums are clumping plants and like to grow in groups. Generally, they must not be divided too frequently or planted singly. Weak seedlings, old seedlings, or diseased seedlings that are too sparse have poor disease resistance. Introduce disease-free, robust new seedlings. Diseased orchid seedlings found should be promptly disinfected and managed in isolation, and only after growth returns to normal can they be placed in the orchid room to prevent cross-infection. Tissue-cultured seedlings and greenhouse seedlings have relatively weak ability to adapt to the natural environment, so they must be carefully tended; do not rush success or try to pull seedlings up to help them grow.

In one sentence: Chinese cymbidiums are killed by fertilizer, killed by medicine, killed by heat, killed by waterlogging, killed by stagnation, killed by division, and also killed by love.