What are the reasons for the yellowing of cassia leaves?
If you want to understand the reasons for the yellowing of cassia leaves, the following is a detailed introduction.
Cassia, scientific name Osmanthus fragrans, is a common ornamental plant, loved by people for its fragrant flowers and elegant tree shape. However, the yellowing of cassia leaves is a common problem, which may be caused by various reasons, including environmental factors, diseases and pests, nutrient deficiencies, etc. Understanding these reasons helps take the correct measures to restore the health of cassia.
1. Environmental factors - Insufficient light: Cassia enjoys ample sunlight, and if it is in a dark environment for a long time, the leaves may turn yellow due to insufficient photosynthesis. Ensure that cassia receives at least 6 hours of direct sunlight every day. - Inappropriate temperature: Cassia has certain adaptability to temperature, but extreme high or low temperatures can cause leaves to turn yellow. The suitable temperature range for cassia growth is 15-28℃, and temperatures too high or too low can cause damage. - Improper humidity: Cassia prefers a humid environment, but excessive humidity can lead to diseases, while low humidity can cause leaves to dehydrate and turn yellow. Maintaining proper air humidity is crucial for the growth of cassia.
2. Improper watering - Excessive watering: Cassia is not tolerant to waterlogging, and if the soil is waterlogged for a long time, the roots will lack oxygen, causing the leaves to turn yellow. The correct approach is to keep the soil moist but not waterlogged, and water thoroughly, waiting until the soil surface is dry before watering again. - Insufficient watering: Although cassia is drought-tolerant, long-term water deficiency can also cause leaves to turn yellow. Especially in dry seasons, it is necessary to check the soil moisture regularly and supplement water as needed.
3. Soil problems - Improper soil pH: Cassia prefers slightly acidic soil, with a pH value between 6.0-6.5. If the soil is too alkaline, it will affect cassia's absorption of nutrients, causing the leaves to turn yellow. Adjusting the soil pH can be done by applying acidic fertilizers like ferrous sulfate. - Soil compaction: Soil compaction can affect root respiration and nutrient absorption, causing leaves to turn yellow. Regularly loosening the soil and applying organic fertilizers can improve soil structure.
4. Nutrient deficiencies - Nitrogen deficiency: Nitrogen is an important element for plant growth, and its deficiency can cause leaves to turn yellow. This can be supplemented by applying nitrogen fertilizers such as urea. - Iron deficiency: Iron deficiency can cause leaves to turn yellow, especially new leaves. This can be supplemented by applying iron fertilizers like ferrous sulfate. - Magnesium deficiency: Magnesium deficiency can cause leaves to turn yellow, especially between the veins. This can be supplemented by applying magnesium fertilizers like magnesium sulfate.
5. Diseases and pests - Leaf spot disease: Leaf spot disease is caused by fungi and can cause yellow spots on leaves. It can be prevented and treated by spraying fungicides such as carbendazim and chlorothalonil. - Red spider mites: Red spider mites are common pests that can cause leaves to turn yellow. They can be controlled by spraying miticides like abamectin and pyridaben. - Aphids: Aphids suck the sap from leaves, causing them to turn yellow. They can be controlled by spraying insecticides like pymetrozine and dinotefuran.
6. Plant aging - Cassia leaves have a certain lifespan, and old leaves will naturally turn yellow and fall off. This is a normal physiological phenomenon and does not require special treatment. Regularly pruning old branches and leaves can promote the growth of new leaves.
7. Improper fertilization - Over-fertilization: Excessive fertilization can lead to high soil solution concentrations, affecting root absorption of water and nutrients, causing leaves to turn yellow. Fertilization should be moderate, following the principle of "frequent application of light fertilizers." - Under-fertilization: Long-term lack of fertilization can lead to nutrient deficiencies and yellow leaves. It is necessary to apply compound fertilizers regularly to supplement nutrients.
8. Transplanting injury - During the transplanting process, the roots of cassia may be damaged, causing leaves to turn yellow. When transplanting, try to preserve the soil around the roots to minimize damage. After transplanting, water thoroughly to promote root recovery.
In summary, the yellowing of cassia leaves is a complex problem that requires considering multiple factors. By adjusting environmental conditions such as light, temperature, and humidity, watering and fertilizing reasonably, preventing and treating diseases and pests, the problem can be effectively solved, restoring the healthy growth of cassia. At the same time, regularly observing the growth of cassia and promptly detecting and addressing issues is also very important.
Have green plant enthusiasts understood the content shared above about the reasons for the yellowing of cassia leaves?