How to protect orchid leaves from damage during orchid care

Since most varieties of Chinese orchids bloom only once a year, the orchid leaves become an important object of appreciation, and there is even a saying that “watching the leaves beats admiring the flowers.” The leaves on each pseudobulb of an orchid grow out all at once and cannot grow new leaves again, which makes the care of orchid leaves all the more important. Based on many years of practical experience growing orchids, the author has summarized a few key points for maintaining orchid leaves, for everyone's reference.

First, avoid damage caused by pests and diseases. Especially during the plum rain season, in the middle and lower reaches of the Yangtze River and areas to the south where there is more rain and higher temperatures, great attention must be paid to preventing waterlogging and the occurrence and spread of diseases, such as scab and southern blight, which mainly damage the leaves, causing spots of varying degrees on the front or back of the leaf surface that are very hard to disappear, and in severe cases the entire leaf withers, so disease prevention must be emphasized.

In early spring, use a thiophanate-methyl solution diluted with 800 times water or a chlorothalonil solution diluted with 500 times water for control, once every 10 days. At the same time, keep the orchid growing area and the pots well ventilated, with appropriate spacing. When orchids develop disease, promptly cut off diseased leaves and old leaves, and the pointed angle formed after cutting should be less than 30 degrees. Leaves damaged by insects can be kept; simply remove the pests. The cut orchid leaves must not be thrown away in the orchid planting area; they should be burned or buried deep.

Second, preserve the leaf tips and prevent the occurrence of tip burn. The tips of orchid leaves should be preserved as much as possible and not easily cut off. Once the leaf tip is lost, the orchid leaf becomes a sword without a point and looks dull. The key to preserving leaf tips lies in careful daily care and management. When the pot is overly wet, old plants are prone to tip burn; when too dry, new plants will have withered tips; excessive heat in the pot, poor ventilation, excessive fertilizing, unclean trimming of rotten roots during repotting, unclean potting medium, and so on, will all cause orchid tip burn. As for the external environment, air humidity that is too high or too low, and poor ventilation with muggy heat, will also cause tip burn.

In addition, there is bacterial tip burn with shrinking heads. When disease spots appear on the leaves, if the scissors are not thoroughly disinfected, bacteria will be introduced into the wound when cutting. The time for cutting off burned tips should be a clear, dry noon, when wounds heal faster; never water after cutting or prune on overcast and rainy days.

The source of tip burn lies in the roots, so to cure tip burn at its root, the pot must be emptied, the root disease source cleaned up, and carbendazim powder applied directly to the wounds. For orchid leaf tip burn, "treating" is passive; even after treatment the leaf is already damaged. Therefore "preventing" is the positive approach: improve management and cultivate with care.

Third, maintain the normal growth posture of orchid leaves and restore their cleanliness. During transport and routine care and management, orchid leaves are easily damaged by external forces, such as breaking, twisting, and tangling, so we must be meticulous in our operations. When spraying water, prevent the water pressure from being too high and folding the orchid leaves over; when sweeping the floor and walking, avoid bumping into the leaves; when twisted leaves are found, straighten them promptly to restore their normal growth state; avoid contaminating the leaves with soil, dust, insect excrement, and bird droppings, because once contaminated, over time it easily leads to leaf disease, so as soon as contamination occurs, it should be washed off immediately.

Fourth, the shade netting must be handled properly. The supports for the shade netting are generally no lower than 2.5 m, as only then can ventilation and air flow be ensured. At the same time, the shading index of the shade netting must reach 70% or more; long-term use of low-density shade netting will cause part or all of the orchid leaves to turn yellow and wither, and it is difficult to restore their green color. However, the orchid shed should avoid being both dark and hot; it should be shaded so that it is both bright and cool, with the best standard being that a person feels cool under the orchid shed.