Don't Worry When the Leaves Turn Yellow
As the star plant of the night garden, Four O'Clocks are deeply loved for their unique fragrance and colorful blooms. However, many enthusiasts often feel at a loss when the leaves start to turn yellow. This article will systematically analyze the top five causes of yellowing leaves in Four O'Clocks, from nutritional management to environmental control, and provide corresponding solutions.
Diagnosis of Maintenance Misconceptions
Double Dangers of Nutritional Imbalance
Over-fertilization can cause new leaves to show dry brown spots and the edges of old leaves to become crispy and fall off. It is recommended to stop fertilizing immediately and use the immersion method to rinse the substrate 3-5 times to dilute the fertilizer. Long-term lack of fertilizer can cause the entire plant to have yellow leaves, requiring monthly supplementation with slow-release fertilizer granules containing nitrogen, phosphorus, and potassium, combined with adding decomposed sheep manure as a base fertilizer during the spring and autumn potting changes.
Golden Rule of Water Management
Yellowing leaves caused by waterlogging often show young leaves with no luster and wilt, and black roots can be observed at the bottom of the pot. At this time, you need to stop watering immediately and loosen the soil for ventilation, and replace the new substrate containing 30% perlite in severe cases. For yellowing leaves due to drought, it is recommended to use the "soak and rehydrate method": soak the pot in a basin of water for 15 minutes, allowing the substrate to absorb water fully before draining.
Key Points of Environmental Control
Accurate Control of Temperature and Humidity
In the high summer temperatures, it is necessary to maintain an environment below 28°C and increase humidity by spraying in the morning and evening. In winter, the maintenance temperature should be kept above 12°C, using a double-layer insulation method: the inner layer with a breathable cotton bag and the outer layer wrapped with insulation film. Special attention should be paid to avoid direct air conditioning and maintain 50%-70% air humidity, which is most beneficial for leaf health.
Graded Management of Light Intensity
In spring and autumn, ensure 4-6 hours of direct sunlight daily, and use a 50% shade net in summer. When leaves start to lose green color, gradually increase the duration of scattered light, avoiding sudden exposure to strong sunlight. For north-facing balconies, it is recommended to pair with full-spectrum plant grow lights, supplementing with 2-3 hours of artificial lighting daily.
By following these five systematic maintenance methods and regularly observing the leaf condition, noticeable improvements can usually be seen within 2-3 weeks. Remember to clean up fallen leaves and maintain good ventilation to make your Four O'Clocks shine again with emerald green leaves.