Causes of yellowing leaves in Chinese roses
If you want to understand the introduction of green plants and flowers that cause the leaves of Chinese roses to turn yellow, it can certainly help you. Let's learn about it together!
Recently, many flower enthusiasts have consulted about the issue of yellowing leaves in Chinese roses. Some of them are caused by improper cultivation, while others are natural metabolic phenomena. Today, let's specifically introduce the factors that can cause yellowing leaves in Chinese roses.
1. Metabolic yellowing leaves of Chinese roses - Now is the peak growing season for Chinese roses. Careful flower enthusiasts will notice that the leaves near the bottom often turn yellow, which is actually a normal metabolic yellowing.
The characteristic of metabolic yellowing leaves is that old leaves occasionally turn yellow. In early spring when Chinese roses sprout, the temperature is often very unstable, fluctuating up and down, so the growth of Chinese roses is slow. These leaves experience unstable temperatures, and after the spring warming, Chinese roses grow rapidly. The bottom of these old leaves receive very little sunlight and have poor ventilation, which can easily cause them to turn yellow and fall off. This is a natural metabolic phenomenon and there is no need to worry. Just clean up the yellow leaves in time.
2. Yellowing leaves due to excessive watering
The most feared yellowing in Chinese roses is waterlogging, which can cause root rot and yellowing of the leaves, making it difficult to deal with. Chinese roses are neutral flowers and cannot be too wet or too dry. Watering should be thorough, allowing the soil to dry out before watering again.
If too much water is poured and the Chinese rose develops root rot, it will cause large areas of the leaves to turn yellow, and both old and new leaves may turn yellow. This is mainly judged by checking the moisture of the potting soil.
3. Yellowing leaves due to excessive drought
Chinese roses can also develop yellow leaves due to excessive drought. Drought-induced yellowing is mainly manifested by the mass yellowing and falling of the old leaves at the bottom, and it will be found that the potting soil is very dry.
For yellowing leaves caused by drought, just clean up the yellow and fallen leaves and water thoroughly to recover.
4. Infection with diseases (black spot disease)
If Chinese roses are not properly cared for, they can easily develop black spot disease, which can also cause a large number of yellow leaves. The main manifestation of black spot disease is the appearance of black or brown spots on the leaves, which can be severe enough to cause yellowing and leaf drop.
Leaves that have fallen from Chinese roses infected with black spot disease must be cleaned up, and fungicides such as mancozeb, carbendazim, and myclobutanil should be sprayed for treatment.
5. Infection with pests
Poor ventilation in Chinese roses can easily lead to an infestation of red spider mites, which are very small mites that gather on the backs of Chinese rose leaves to absorb sap. This can cause pinhead-sized spots on the leaves, making them look dense and causing the leaves to turn yellow.
Chinese roses affected by red spider mites should be treated promptly with miticides such as pyridaben, jinmanzhi, aikaren, and abamectin. Spray every 5-7 days, with 3-4 consecutive applications for complete eradication.
6. Yellowing leaves due to nutrient deficiency