Reasons and Solutions for the Yellowing of Moorchid Leaves
As an important member of the national orchid family, Moorchid is deeply favored by orchid enthusiasts for its elegant leaf posture and refreshing fragrance. However, yellowing of leaves is a common problem during maintenance, which not only affects the ornamental value but may also endanger the plant's health. This article will systematically analyze the three main causes of Moorchid leaf yellowing and provide scientific solutions.
I. Natural Regulation of Physiological Yellowing
1.1 Metabolic Mechanism
Moorchid undergoes 2-3 leaf renewal cycles annually, usually during the spring and autumn seasons. The gradual yellowing of the bottom 3-4 old leaves is a normal metabolic phenomenon, as the plant abandons old leaves to concentrate nutrients for the growth of new buds.
1.2 Scientific Pruning Techniques
After the yellow leaves have completely dried out, use gardening shears that have been disinfected with alcohol to cut at a 45-degree angle along the base of the leaf sheath. After pruning, apply wood ash to the cut to prevent infection and maintain good ventilation. Be sure to leave 2cm of the leaf sheath base to protect the pseudobulb.
II. Prevention and Control System for Waterlogging Yellowing
2.1 Symptoms of Root Hypoxia
When the growing medium remains moist for more than 72 hours, typical symptoms such as the tip of new leaves becoming withered and old leaves quickly yellowing will appear. Pulling out the plant will show that white fleshy roots have turned brown and have a foul odor.
2.2 Emergency Treatment Plan
Immediately stop watering and invert the pot to drain the accumulated water. Move the plant to a shaded area to air-dry the roots for 24 hours, then soak in a solution of 800 times the concentration of carbendazim for 30 minutes. Replace the old medium with a new mix of pine bark: volcanic rock: perlite = 5:3:2 and repot.
III. Precision Regulation of Nutritional Yellowing
3.1 Deficiency Identification Guide
If interveinal yellowing occurs during the peak growing season in August, it is often caused by nitrogen deficiency; if the tip of the leaves becomes withered and curled, it indicates potassium deficiency; and if new leaves turn yellow and white, it suggests iron deficiency. It is recommended to irrigate with a nutrient solution with an EC value of 0.8ms/cm twice a month.
3.2 Scientific Fertilization Strategy
Follow the principle of frequent application of thin fertilizers. Use a balanced 20-20-20 water-soluble fertilizer from April to June, and switch to a high phosphorus-potassium formula of 10-30-20 from July to September. After fertilizing, rinse the leaf heart with water to prevent fertilizer damage.
With the above systematic solutions, more than 90% of Moorchid leaf yellowing problems can be effectively controlled. It is recommended that orchid enthusiasts keep a maintenance log, recording watering and fertilizing times, and regularly check the pH value of the medium (which should be maintained between 5.5-6.5). Once the plant recovers, gradually increase the light intensity to 5000-8000lux to help the Moorchid regain its elegant, upright posture.