How to solve the blackening of the leaves of azaleas

Your cuckoo is likely to have brown spot or black spot. This may have something to do with your current environment, which is too humid or poorly ventilated.

Brown spot disease is a major disease of rhododendrons. At the beginning of the disease, small brown spots appear on the leaf surface, which gradually develop into irregular large spots, and many black or gray-brown spots are produced on the lesions, which make the affected leaves turn yellow and fall off, affecting the flowering of the current year and the development of flower buds in the next year. This disease often occurs during the rainy season when the humidity is high.

If the ambient air in the vicinity of cultivation is polluted, it is also easy to cause spots on the leaves. The spores of the fungus will scatter in the potting soil, and first grow hyphae on the old and weak leaves, and soon spread, causing the leaves to fall off from the bottom up.

**The method is to pay attention to the ventilation and light transmission of the plants, do not make the humidity too large, and increase the application of organic fertilizer and nitrogen, phosphorus and potassium mixed fertilizer to enhance the plant's resistance to infection and growth. If diseased leaves are found, they should be removed in time and burned in a centralized manner. At the beginning of the disease, spray 0 5 Bordeaux liquid or 0 4 Baumé stone sulfur mixture, and add 4 flour to increase adhesion.

The same method can be used for leaf spot and black spot**.

The blackening of the azalea leaves may be caused by direct exposure to strong sunlight. When the leaves lose their greenness after being sunburned, they will turn black and fall off. The blackened leaves are cut off and replaced with bright and gentle scattered light nourishment to ensure healthy leaf development.

Watering too much or too little can cause the azalea leaves to turn black. Too much water in the environment is too wet, forming water hazards, and too little water irrigation will cause drought in the potting soil. According to different water hazards, adjust the amount of water in the potting soil to alleviate the blackening of leaves.

If too much fertilizer is applied beyond the limits that the rhododendron can tolerate, it is easy to form fertilizer damage in the potting soil. Fertilizer damage is more harmful, not only will the leaves turn black, but in the long run, the rhizome will also rot. Dilute the excessive fertilizer in the potting soil as soon as possible, and then take the method of thin fertilizer and frequent application to add pests and diseases in the rhododendron growth environment due to improper maintenance, which will suck the nutrients in the leaves and branches, causing the leaves to grow uncomfortably, black and wilted.

Farmers should prune off these leaves in time, and spray pesticides to eliminate bacteria and insects after concentrated burning.

For black spot disease, spray 50% carbendazim 500 600 times solution for prevention and control.

Raise rhododendrons, and the black leaf tips are treated like this, and they can easily turn back to green.

(1) Specific reasons: This plant has high requirements for water. If you give too much, or too little, it may cause the leaves to turn black.

2) Solution: So, in general, the number of times the water is given should not be too frequent. Observe the condition of the soil surface and wait until it is dry before watering. According to this, the watering interval is determined, which is more flexible and effective.

(1) Specific reasons: Like water, too much or too little fertilizer may cause the leaves to turn black.

2) Solution: There is a general principle of fertilization, which is "thin fertilizer and diligent application". Of course, "diligence" does not mean that the number of times can be too much, appropriate is the best. The most important thing is the concentration, which should never be too high.

1) the specific reason; In addition to pouring, the humidity of the air also has an effect on it. If it is too low, it will also cause its leaves to turn black.

2) Solution: Specifically, it is better to keep it at 60 to 80 percent. We can improve it by placing a basin of water next to it or by spraying some mist around it.

(1) Specific reason: This plant requires a semi-shaded environment. Then, if the light is too strong, it will inevitably burn the leaves and it will turn black.

2) Solution: Observe the position of the plant and whether it will be exposed to direct light. If you can, then you have to adjust in time.

1) Specific causes: Specifically, "brown spot disease". At the beginning of the disease, it is a small spot. Later, there is a chance that the entire leaf will turn black.

2) Solution: Dispose of the infected leaves first. Then, spray some medicine, such as chlorothalonil.

Rhododendron is a very characteristic flower, most people will be at home because of too strong light, poor ventilation, improper fertilization, fungus and insect infestation and other reasons cause the edge of the leaf of the rhododendron to be black, the leaf surface is dry and easy to fall off.

1. The light is too strong.

Rhododendron likes to be nourished by warm and bright light during its growth, but it is difficult for azalea leaves to adapt to the strong light and strong ultraviolet rays in summer. The leaves themselves are also relatively fragile, and direct sunlight will cause sunburn, and the rhododendron leaves will be black and dry.

2. Poor ventilation.

The ventilated environment is always forgotten during the growth of azaleas. A good ventilation environment can not only avoid the invasion of germs and insect pests, but also make the growth temperature balance in a moderate range. Especially in the scorching heat environment, the ventilation is not smooth, and the plants are kept in a closed environment, and the leaves will be intolerant, black and dry.

3. Fertilizer damage.

Fertilizing rhododendrons should adhere to the principle of "thin fertilizer diligently", because the fertilizer tolerance of azaleas itself is very poor, and some novices will apply fertilizer frantically in order to make rhododendrons bloom during the flowering period, which is wrong. Fertilizer damage will burn the rhizome, corrode the growth of stems and leaves, and the leaves will be black and dry if they are not nutritious.

4. Bacteria and insect pests.

In addition to improper farming, azaleas are also at risk of pests and diseases. In particular, the main symptom of common brown spot and black spot is that the leaves of rhododendrons are black and dry. In addition to pruning and removing them as soon as possible, it is also necessary to spray pesticides to remove diseases and residual eggs.

Growth habits of rhododendrons:

Rhododendron is very demanding in the growing environment, it likes to grow in acidic, moist soil, and it likes to thrive in the sun. Rhododendron is afraid of agricultural fertilizer when growing, avoid exposure to the sun, and fear drought and flood. If the improper way of potted cultivation at home will cause one year of flowering, two years of yellow leaves, and three years of leaf loss.

When the leaves of azaleas appear, they are generally caused by too high temperature, too much watering, too much fertilization, direct sunlight, and the pH value of the soil does not match.

Rhododendron is more harmful due to the constant wetness of the potting soil than it is from dryness, and if the condition is severe, it is often impossible to salvage. The symptoms of plants damaged by the constant wetness of the potting soil are moldy root rot, yellowing of young leaves, small and thin old leaves, and black spots on the leaves in severe cases, and then the leaves fall off one after another, and only a few pale yellow young leaves remain on the branches.

The reason for the blackening, dryness, and loss of the leaves of the rhododendron is due to improper light, improper watering, and excessive fertilization. Rhododendron is a light-loving plant, insufficient light will cause the leaves to yellow and fall, but the daily maintenance of the light should not be too strong, otherwise it will lead to too fast loss of water in the leaves, resulting in blackening, drying, and falling of the leaves. When breeding Xishan Xun rhododendron, it should be noted that the amount of watering should not be too much, otherwise it will lead to soil water accumulation and affect the growth of rhododendron roots.

Growth habits of rhododendrons:Rhododendron likes a warm growth environment, the growth temperature is 12 25, the summer temperature is more than 35, then the new shoots, new leaves grow slowly, in a semi-dormant state, when the winter temperature is lower than 0, the plant is easy to be frostbitten, need to move it to a warm environment for maintenance.

Rhododendron needs a lot of nutrients during the growth period, pay attention to the fertilization concentration should not be too high, otherwise it will burn the root system of the plant, affect the growth of the rhododendron, and can not apply a single fertilizer, otherwise it will cause the rhododendron to grow, and the water can be properly replenished after fertilization.

1.The blackened and dry tips of the rhododendrons are mostly caused by four conditions.

2.First, improper watering, the soil is too dry or there is stagnant water, which will hinder growth and is prone to this situation.

3.The second is low humidity, it likes a high humidity environment, and the environment is too dry to grow.

4.The third is that the light is too strong, and they are afraid of direct light, which will sunburn the plants.

5.Fourth, excessive fertilization burns the roots, and the leaves are easy to appear black and dry.

Rhododendron roots blackened, we need to cut off these roots, and then disinfect its wounds, soil discomfort will cause its roots to appear black and rotten, so it is also necessary to replace new soil, there may be improper water and fertilizer caused by its roots blackened, so after the maintenance of azaleas should be reasonably applied water and fertilizer.

1. Pruning and disinfection

The blackening of the roots of the rhododendron is generally due to improper maintenance of its root system to breed germs, this time we need to cut off the blackened parts of its roots first, and then we also need to use carbendazim and other disinfectant solutions to disinfect its wounds, so that it can survive.

2. Replace the soil

Rhododendron likes to grow in loose, fertile and well-drained slightly acidic sandy soil, if the soil is too clay and heavy or the acre is alkaline, its root system is prone to blackening, so at this time we also need to replace it with new soil, so as not to black and rot its roots again.

3. Reasonable watering

Although the rhododendron likes to grow in a humid environment, it is not resistant to waterlogging, if the soil is produced by stagnant water, its root system is easy to blacken, so when the azalea is maintained, it needs to be watered according to the dryness and humidity of the soil, and it is best to keep the soil in a moist but not wet state.

4. Correct fertilization

The roots of the rhododendron are blackened, and it may be caused by improper fertilization, if it is applied with raw fertilizer or thick fertilizer, it will cause it to produce fertilizer damage, which will make its roots black and rotten, so we need to master the principle of thin fertilizer and frequent application of rhododendron fertilization, and stop fertilizing when the plant is dormant.

Rhododendron can be infected with brown spot or erythema. Prevention and control can be carried out according to the onset symptoms of leaves.

Introduction: Rhododendron, one of the top ten famous flowers in China. Flower in the Shih Tzu, alias:

Yingshan red, mountain pomegranate, mountain heel, red heel, Jindalai, mountain cuckoo, red azalea, Yanshan red, Yanshan flower, Qingming flower, Gesang flower (Tibetan), Jindalai (Korean), mountain pomegranate, etc. Among all the ornamental flowers and trees, it can be called beautiful flowers and leaves, and it is suitable for ground plants and potted plants, and it is the most widely used. In the natural distribution of azaleas in the world, there are many kinds and huge quantities, none of them can match China, and China is a treasure trove of rhododendron resources in the world!

Nowadays, Jiangxi, Anhui and Guizhou take azalea as the provincial flower, and there are as many as seven or eight cities that are designated as the city flower, which shows people's love for rhododendron. When the azaleas are in full bloom, just when the cuckoo bird is crying, the ancients left many poems and beautiful and moving legends, and there is a custom of taking flowers as a festival. Rhododendron is mostly a shrub or small tree, which has its own living habits and shapes due to different ecological environments.

The smallest plants are only a few centimeters tall and are cushion-shaped and close to the ground. The largest is several feet tall and stands majestically and magnificently.

There are many reasons why azaleas turn black, so there are many possibilities that can cause azalea leaves to turn black, such as: watering the azalea, inappropriate ambient temperature, improper lighting conditions, etc., all of which can cause the azalea leaves to turn black. Unsuitable ambient temperature, improper lighting conditions, etc., can cause the leaves of azaleas to turn black.

In addition to the effects of watering and temperature on azaleas, if not properly maintained, it is possible to cause the leaves of azaleas to turn black. The light conditions of the azalea should be in semi-shade, or there should be scattered light.

That means that there is a problem with the root system, there is a problem with the stem and leaves, that is the problem of the root system, it is best to check the root system, if the root system is wrong, then the plant can not be wanted.