Overview of azalea diseases and pests. What to do to make a green friend healthy?

Azaleas (or, as they are also called, rhododendrons) are flowering plants grown at home and in the open. Potted evergreen shrubs require maintenance in certain conditions - cool air and high humidity. They are sensitive to soil composition, lighting and watering. Violation of agricultural recommendations leads to weakening of the plant. A low immunity azalea is defenseless against diseases and pests. From the article you will learn about the ailments of rhododendron (such as brown stems and roots, falling leaves, etc.), see their photos, get acquainted with the methods of treating diseases and controlling pests.

What can indoor rhododendron suffer from?

Plant disease is a negative condition caused by viruses, bacteria, fungi, or improper care. Azaleas respond to lack and excess of nutrients, the degree of soil moisture. Characteristic symptoms:

• drying leaves and buds;
• discoloration, the appearance of spots;
• falling of leaves and flowers;
• rotting of the roots;
• growth retardation.

Pests are insects that have settled on a plant. Phytophages feed on azalea juice, causing wilting, yellowing of leaves and deformation of buds. One of the dangers is the spread of pests of viruses and fungal infections.

How to determine the cause of the disease?

Noticing the deterioration of the indoor plant, you should carefully examine it and the soil in the pot. If small pest phytophages are found, then you need to fight them. Usually insects are found in greenhouses and garden specimens, but they also get into the house without problems. In other cases, they review agricultural care and study the symptoms of the disease.

To establish the cause of the disease, you must:

1. Take into account all agricultural factors:
   • frequency of watering;
   • soil composition;
   • top dressing;
   • temperature
   • humidity level;
   • illumination.

   Deviations from the recommended norms for azalea lead to a deterioration of the plant.

2. To study the signs of fungal infections and the effects of pests, compare them with the state of the plant.

Danger to the plant

Diseases harm the decorative appearance of indoor and garden plants. Fallen or deformed leaves, withered buds, discoloration - all this creates a depressing impression. Lack of treatment and taking measures to improve the conditions of detention threatens the death of the bush. The sooner resuscitation of a flower begins, the more chances there are to regain its health.

Home Treatment Methods

Disease treatment is an integral part of flower care. Most of the problems are eliminated by establishing optimal conditions. In the fight against infections and viruses, special drugs will be required. Common azalea problems include the following.

Bush drying

The main causes of drying out of azalea are:

• insufficient watering;
• high temperature in the room;
• violation of moisture conditions.

In the first case, it is recommended to increase the volume of water during irrigation. The soil must be moistened after the top layer has dried. If the lump of earth is too dry, the water does not linger in it. To nourish the plant with moisture, the pot is lowered into a container of water for 15-20 minutes.

Azalea prefers cool, in the heat it loses turgor of leaves and withers. In summer, the plant is kept at a temperature of no higher than 20-22 °, and in winter - 15-16 °. For azaleas, you should find a place away from heating appliances.

An evergreen plant requires timely watering and moist air. During the operation of heating devices, the problem of dry air is solved by additional humidification. A pot of azalea is placed on a pallet with wet expanded clay or pebbles.

More information on why the azalea leaves dry and what to do in this case, you will find in a separate article.

Yellowing crown

A change in the color of the leaves occurs when the soil is impoverished and the content of calcium salts is high. Using hard water for irrigation changes the acidity of the soil. In alkaline and neutral soil, azalea does not absorb iron and magnesium well. The result is chlorosis. For treatment, it is necessary to water the plant with acidified water (3 drops of lemon per 1 liter of water) and make mineral fertilizers for azaleas.

Read more about why rhododendron leaves turn yellow and other organs and how to save the plant, we wrote here.

Blackening foliage

An examination of the plant and the nature of the spread of the problem will help determine the cause of darkening of the leaves.

• Black spots on the inside of the leaf plate may indicate a black thrips lesion. The pest is destroyed by the emulsion of Karbofos.
• The spread of darkening on the stem is similar to the manifestation of Fusarium. Adjusting the diagnosis will allow watering - the deterioration of the plant confirms a fungal infection.

With a small defeat, the bush is saved by the treatment with Fundazol. In the late stage, azalea cannot be saved. It is destroyed along with the soil in order to prevent the spread of the disease.

What to do if the azaleas turn black and fall, you will learn in our article.

Shedding of leaves and buds

Leaf loss is a common problem in recently purchased azaleas. They suffer from a lack of nutrients in the soil and changes in climatic conditions. To save the plant, the following actions are recommended:

1. Transfer the bush to a larger diameter pot, fill the empty space with soil for azaleas.
2. Spray the plant with a growth stimulator - Novosil or Epin.
3. Place the bush under a plastic film that provides high humidity and a stable microclimate.
4. Ventilate the plant daily.

The cause of leaf loss may be regular waterlogging.causing root decay.

1. To assess the state of the root system, the plant is taken out of the pot along with a lump of soil. Healthy roots are white, diseased are brown.
2. The affected parts are removed, the slice is covered with crushed activated carbon.
3. Excess moisture is removed from the ground by air drying.
4. After a day, the azalea is returned to the pot.
5. Then strictly follow the watering.

You will find more information on why azalea drops leaves and what to do to solve the problem in this material, but here we wrote about how to save a withering indoor plant.

Diseases due to improper care

Errors in the care of azalea lead to damage to its organs and premature death:

• Low air temperature causes necrosis - the death of the main axis of the leaf. It takes on a brown tint. Leaves are not restored, they are removed.
• Abundant watering and lack of top dressing for several months cause mixed chlorosis. The tips of the leaves turn yellow and dry. For treatment, foliar top dressing with iron and magnesium is required.
• Improper care (excessive watering, lack of drainage, low temperature) provokes the appearance of fungal diseases.

Fungal infections

Infection with a fungus occurs through the soil, tools, diseased plants. Characteristic signs are the appearance of spots, putrefactive lesions, plaque.

1. Fusarium - through the roots, the pathogen penetrates the blood vessels of the plant and prevents the movement of nutrients. Starting from the top of the azalea, the leaves fade, turn brown and fall off. A pink coating appears on the root neck. The bush is isolated and treated with a solution of Fundazol.
2. Alternariosis - the appearance on the leaves of red-brown spots of various shapes. It is treated with Bordeaux liquid and fungicides.
3. Phyllocystosis - the fungus provokes the appearance of brown spots with a darker border. Their middle dries and gets enough sleep. The affected parts are removed, the plant is alternately sprayed with a solution of Fundazole and Topsin-M.
4. Cercosporosis - brown spots with a red border are formed on the lower part of the leaf plate. The top is covered with a gray coating. Azalea is treated with fungicides - "Ditan M-45" and "Fundazol".

Insects and control measures

A common cause of the disease and death of azalea is the appearance of pests:

• Rhododendron bug - winged insect 3-3.5 mm in size. Lays eggs on the back of the leaves, covering them with tarry discharge. Adults and larvae suck plant juice. Leaves turn yellow and curl. Pests are destroyed by Decis, Fury insecticides.
• Mealybug - the body of the parasite is covered with a white waxy coating. It affects all parts of the plant. Discharges of worms contribute to the spread of soot fungi. Control measure: treatment with Actellik.
• Weevil - adult beetles eat around the edges of leaves, buds and buds. Larvae in the soil damage the roots. Against weevils use means - "Bazudin", "Aktara".
• Chipper - the beetle eats leaves, leaving only veins. The remedy is Diazinon.
• Slug - feed at night on young plants, eating leaf buds. Insects are collected using traps, "Mesurol" is used.
• Thrips - greenhouse or black thrips eats azalea leaves. Due to damage, they turn yellow and fall off. Insects are removed with a solution of Karbofos.
• Mole - the pest of the bush is the caterpillars of the azalea moth. They feed and pupate on the leaves. Fumigation and sulfur spraying are used against the pest.
• Fly - Rhododendron fly is a specific pest sucking juice from leaves. Nicotine sulfate is disposed of.
• Aphid - small insects live in colonies. Their vital activity slows the growth of bushes, leading to a delay in flowering. Aphids carry viruses. In the fight against the pest, Karbofos and Aktellik are used.
• Whitefly - butterfly sucking azalea juice. The plant lags behind in growth, withers and dies. The bushes are washed with soapy water and sprayed with Aktara.
• Mite - on the azaleas, 3 species of ticks parasitize - red, strawberry and spider. Adults and larvae damage the tops of shoots, flowers, leaves. Pests hide on the back of the leaves, making detection difficult. To kill ticks, use Actellik.

Watch a video about which pests affect azalea and how to deal with them.

Photo

Below you can see photos of common diseases and pests of azalea.

Preventive measures

Preventive measures can prevent plant diseases:

1. Maintaining cleanliness in areas containing azaleas.
2. Treat the bush with copper chloride in the minimum dosage.
3. Use pure water for watering and spraying.
4. Disinfect tools, sterilize soil and pots.
5. Feed the plant with organic fertilizers.

Further care

The main recommendations for flower care are as follows:

• The shrub needs good lighting, but without direct sunlight.
• Feeding is recommended in summer and autumn, before setting buds. Fertilizer concentration is best reduced by 1.5 times.
• Watering only with soft water - thawed or boiled, acidify with lemon once a week.
• Avoid drafts and sudden changes in temperature.
• Dry air is harmful to the plant.
• At temperatures below 15 ° C, azaleas are not sprayed.

There are enough modern drugs to combat diseases and pests of ornamental plants. But it is more important to provide the flowers with optimal conditions under which problems will not arise. Caring for azaleas is not easy, but abundant and prolonged flowering of bushes will be a worthy reward for your efforts.

Watch the video: Cure for Azalea Lace bugs (December 2024).