What causes orchid leaves to turn yellow?

Orchid is a plant that requires careful care. Although it is easy to survive, it is not easy to grow well. The key to orchid maintenance lies in the environment, but even if the environmental conditions are good, the orchid's leaf tips may sometimes become burnt or black during the maintenance process. So what is the reason why orchid leaves turn yellow?

1. Excessive watering or poor ventilation of the planting material

If several orchid leaves in the pot turn yellow, in severe cases, the newly grown heart leaves may also turn yellow or burnt. This may be caused by too frequent watering or the planting material is too fine and solid and lacks ventilation. The solution is to control watering frequency, increase ventilation, and loosen the planting material.

2. Drought

If all the orchid leaves in the pot are slightly yellow, the color is uniform but lacks luster, and in severe cases the orchid leaves appear weak and powerless, this may be a sign of drought. The solution is to water in time and spray water on the leaves to speed up recovery.

3. Too much sunlight

If the entire orchid pot appears dry and yellow, the leaves appear old and hard, and in severe cases some leaves have burns, this may be the result of excessive sunlight. The solution is to adjust the shading according to the season, especially in summer and autumn, the shading rate should reach 80%~90%.

4. Lack of nitrogen fertilizer in fertilization

If the leaves of the orchid in the entire pot are yellow-green, uniform in color and shiny, the orchid looks healthier, but it actually lacks nitrogen fertilizer. The solution is to increase the application of nitrogen fertilizers, such as Huabao No. 5, urea, etc., and dilute them strictly according to the instructions, generally 1000~2000 times the liquid, to avoid excessive concentration. Organic fertilizers , such as rapeseed cake and liquid fertilizer made from fish, contain more nitrogen and can be diluted 100 times before application.

5. The pH of the planting material is not suitable

If some orchid leaves turn yellow, especially the base leaves, and the front ends of the leaves turn yellow and then turn gray to black, and the diseased leaves are weak and powerless, this may be because the pH value of the planting material is low or alkaline. Orchids grow best in slightly acidic planting materials (pH 5.5~6.5). The solution is to use 1000 times diluted ferrous sulfate to spray the leaves and water the plants.

6. Nutrient transfer to new shoots

The base leaves of some orchid plants will turn yellow when they sprout. This is a normal phenomenon of nutrients being transferred to the small buds, which is called "pregnancy jaundice." This yellowing of leaves is limited to the foot leaves, the leaf surface is smooth and shiny, and will eventually fall off naturally. If you find this situation, it means that small buds have begun to sprout on the pseudobulb. You can cut off the yellow leaves to concentrate nutrients on the small buds, or let nature take its course.

In response to these reasons, appropriate remedial measures can be taken, such as reasonable fertilization, adjustment of watering, improvement of lighting conditions, prevention and control of diseases and pests, etc., to restore the healthy growth of orchids.