What Causes the Leaves of Roses to Turn Yellow
If you want to know why the leaves of roses turn yellow and a brief solution for yellowing leaves in the field of green plants and flowers, the following content will be shared in detail.
Roses are one of the top ten famous flowers in China. They have many varieties and a long blooming period, making them deeply loved by everyone. Since they are not very demanding in terms of climate and soil, they can be planted in many places and are widely distributed in China. However, although they are common, it is not easy to grow them well. If the environment is not suitable or the maintenance is improper, the plants may show symptoms of yellowing leaves and wilt. In this case, we need to find the reasons for the yellowing leaves and take corresponding treatment measures.
I. Fungal Diseases
Roses may suffer from fungal infections during their growing period. Yellow spots will appear on their leaves and gradually spread, eventually causing the entire leaf to turn yellow.
Fungal diseases are often caused by humid weather or excessive watering, as these conditions are more conducive to the growth of fungi. If ventilation is poor, their growth and spread will be even faster.
To prevent fungal infections, it is first necessary to improve air circulation, which can not only inhibit fungal growth but also accelerate the evaporation of water. After the plant is affected by the disease, it is necessary to cut off the diseased branches and leaves and spray fungicides such as carbendazim for control.
II. Improper Watering
Roses are sensitive to water, and both too little and too much watering can cause problems. Excessive watering may trigger various diseases and also has the risk of root rot. Insufficient watering will cause the plant to dry and wilt due to lack of water.
There are many factors to consider in daily watering, such as temperature or humidity. When the temperature is high, more water should be given to roses to prevent excessive water loss and leaf yellowing due to lack of water. If the humidity is too high, watering should be reduced to avoid积水, which is not conducive to growth.
Before watering roses, you can first check the moisture level of the potting soil. Generally, water should be added after the soil is completely dry, and each watering should be thorough but without积水. This allows the plant to absorb sufficient water without affecting the root respiration.
III. Pest Infestation
There are many pests that can affect the growth of roses, such as inchworms, scale insects, and aphids. Some pests feed on the leaves, while others absorb the sap of the plant, causing insufficient nutrients and leading to yellowing leaves.
Pests appear due to environmental issues or the failure to eliminate the remaining eggs in the potting soil after previous pest control measures, leading to their resurgence when the temperature recovers.
Therefore, eliminating pests must address the root cause, or they will return the following year. For aphids, pyrethrin can be used for extermination, scale insects need to be captured manually, and their larvae can be eliminated by spraying pyridaben. Every spring, it is necessary to change the potting soil, and the original soil can be exposed to sunlight to help eliminate eggs.
IV. Lack of Nutrients
Plant growth not only requires nitrogen, phosphorus, and potassium but also various trace elements. If the nutrients in the potting soil are deficient, the plant may also show yellowing leaves, and the appearance of yellowing leaves will vary depending on the nutrient deficiency.