What to Do When Camellia Leaves Develop Black Spots? Causes and Solutions

As one of China's famous flowers, the camellia also ranks among the top in international floral art. The camellia's flower colors are very beautiful, and because there are so many varieties of camellia, the flowers come in all kinds of colors, making them deeply loved by people. They are generally grown mostly in the south, but the survival rate of camellias is not high, and growing them also requires skill. When they are affected by some pests and diseases that cause black spots on the leaves, what are the reasons? What should we do? Below, Shuaishuai will tell everyone!

1. Leaf spot disease

1. Causes

Black spots appearing on camellia leaves may mean they have been infected with leaf spot disease. Leaf spot disease is also a problem that many growers have encountered. It is a disease that specifically harms plant leaves. The symptoms in the early stage of onset are blackish-brown spots appearing on the leaves, which then gradually increase in number, spread outward, and finally become more and more numerous, covering the entire leaf, causing the leaf to die and fall off, and then infecting other leaves. Some lesions also appear grayish-brown and grayish-white. The reason camellias become infected with leaf spot disease is mostly that the air is too hot and humid and not ventilated, giving pathogens the conditions to breed. Overwatering is also one of the causes. Once water accumulates, it causes the root system to rot, and at this time pathogens take the opportunity to invade and infect the plant. These pathogens can spread through many pathways, causing more leaves and plants to become infected with leaf spot disease.

2. Solutions

If your camellia has become infected with leaf spot disease, you need to pay attention to these points. When watering, do not splash water onto the leaves, as this will worsen the condition. If there is water on diseased leaves, it will provide nutrients for the pathogens. In addition, before overwintering, first cut off all infected leaves, and then spray with lime sulfur mixture for treatment. During this period, take care to protect the leaves from sunburn and frostbite, control the temperature variation in the surrounding environment, and it is best to move them back indoors to grow under scattered light. In ordinary care, we can buy chemicals to spray, which can supplement nutrients and prevent diseases, reducing the rate at which camellias get sick.

2. Sooty mold

1. Causes

Sooty mold is very similar to leaf spot disease, and the symptoms are also very similar. If a camellia has sooty mold, black spots will form on the surface of the leaves. These lesions are also grayish-brown in the early stage of onset, but later they are different, eventually turning from grayish-brown to black, and then slowly expanding the range of the pathogen, harming the entire leaf and other leaves. The conditions for the growth and infection of sooty mold are a hot, humid, and unventilated environment, and it is a fungal infection contracted through damage by aphids and scale insects. The higher the humidity and temperature in the ambient air, the faster sooty mold develops, and the black lesions will affect the plant's photosynthesis, causing damage to the plant's chlorophyll synthesis and other aspects, which is very unfavorable to the growth of camellias.

2. Solutions

First, prevent and control it from the root. We first adjust the growing environment of the diseased plant, move the plant to an environment with air circulation and moderate light for cultivation, then wipe all the diseased leaves of the plant with clean water, wiping away the lesions and some pathogens, and then we can buy some chemicals on the market for preventing and controlling aphids and scale insects and spray them, which can prevent the infection rate of pests. Usually, once pests are found, they can be wiped away with a cloth.

The above are the causes and solutions for black spots on camellia leaves. Generally, the reason camellias develop black spots is that they are caused by leaf spot disease and sooty mold. These two pathogens specifically harm plant leaves, so during cultivation we must destroy the growing conditions of the pests, not give them conditions to reproduce, inhibit their spread, and then do some prevention work and spray chemicals.