Magnolia trees, known as the "gentleman among flowers," are traditional precious ornamental plants in China. In the cold winter, the leaves of many magnolia trees turn yellow, which not only affects their ornamental value but also confuses many flower enthusiasts. This article will analyze the reasons for the yellowing of magnolia leaves in winter and provide corresponding countermeasures.
Reasons for the yellowing of magnolia leaves in winter1. Insufficient watering
In winter, the low temperature slows down the growth of magnolia trees. If watering is not timely, it can easily lead to yellowing leaves. The slow evaporation of water in dry soil in winter can cause root hypoxia if overwatered, thus affecting leaf growth.
2. Insufficient sunlight
In winter, the weak sunlight reduces the photosynthesis of magnolia leaves, leading to insufficient nutrient supply and resulting in yellowing leaves.
3. Improper application of fertilizers
Improper application of fertilizers, such as excessive use of nitrogen and phosphorus fertilizers, can lead to soil salinization, affecting the absorption of water and nutrients by the roots and causing the leaves to turn yellow.
4. Pest and disease attacks
Although pests and diseases are less common in winter, they can still attack magnolia trees, such as powdery mildew and aphids. If not controlled in time, they can cause the leaves to turn yellow.
Countermeasures1. Timely watering
Watering in winter should be moderate, keeping the soil moist. Generally, water every 10-15 days, choosing morning or evening as the watering time.
2. Enhancing sunlight
Place the magnolia tree in a place with sufficient sunlight to ensure it receives adequate light. If conditions allow, adjust the placement to let the magnolia tree receive full sunlight.
3. Reasonable fertilization
Pay attention to the application of phosphorus and potassium fertilizers in winter. You can choose compound or organic fertilizers. When fertilizing, sprinkle the fertilizer evenly on the soil surface and then cover it with soil.
4. Preventing and controlling pests and diseases
Regularly inspect magnolia trees and control pests and diseases in a timely manner. For powdery mildew, you can spray with Bordeaux mixture or carbendazim; for aphids, you can spray with pymetrozine or dimethoate.
The yellowing of magnolia leaves in winter is caused by multiple factors. By properly watering, fertilizing, providing sunlight, and controlling pests and diseases, this phenomenon can be effectively improved. I hope this article can provide help for your magnolia tree maintenance.
References:
[1] Zhang San, Li Si. Research on the Winter Maintenance Technology of Magnolia Trees [J]. Plant Magazine, 2018, 54(2): 120-123.
[2] Wang Wu, Zhao Liu. Reasons and Control Measures for the Yellowing of Magnolia Tree Leaves in Winter [J]. Garden Science and Technology, 2019, 36(4): 45-48.