Rhododendron leaves turn yellow after winter. Why do leaves turn yellow? How to reanimate after pests

Failed landing

Too light, dull, small leaves; oppressed look. This indicates a lack of oxygen to the roots (wet dense soil, stagnant water) or a lack of nutrition or water.

How to save. Right . They plant a rhododendron in and make sure that there is no competition with a superficial root system. Even too active perennials such as tenacity, completely covered trunk circle rhododendron, can deprive it of nutrition and moisture.

Often the outer part of the root ball is also a container formed by dead roots. Their dense felt does not allow living roots to break into the soil - as a result, the plant starves. It is necessary to remove this inner container when planting, or at least notch it in several places. It is useful to check if there are mole or mouse passages in the root zone.

How can I help you. , if necessary, water and mulch plantings, spray the crown. If the plant is planted well, but still lags behind in growth, they can help foliar top dressing solution of complete mineral fertilizer with trace elements. Top dressing is required 3-4 times in June-July at half the dosage recommended in the instructions.

Such a root ball before planting should be freed from a layer of dead roots.

Unsuccessful wintering

Death of leaf tissues or buds on parts of the rhododendron that are above the snow. The problem arises from the alternation of daytime sun and nighttime frost in February and March. If cold weather is accompanied by wind, then the leaves of the plant actively evaporate water. The water supply is not replenished, because the roots in the frozen ground do not work, and the leaves simply dry out. In deciduous species of rhododendron, flower buds or the upper parts of the shoots may dry out.

How to save. When choosing a landing site. In dry autumn, plants are watered abundantly. They install a winter shade - a mesh or gauze, a rare burlap on the frame, a protective screen, and the like. In autumn, bushes are mulched with a layer of 7-10 cm so that the soil does not freeze deeply.

How can I help you. In the spring, severely damaged leaves are pruned. The shoots are pruned in June, when it becomes clear where the buds wake up. Do not rush to cut branches from small-leaved evergreen rhododendrons - they very often grow back over the entire length of the shoot. If the leaves remain in a winter state for too long - lowered and rolled into a tube - the crown is often sprayed with water. They rake, so that the earth thaws rather, and the roots work.

Fracture of bushes by settling infusion or wet snow

How to save. In autumn, structures are installed above the bush, which will take on part of the snow load: arcs fixed crosswise, wigwam from stakes, etc. If the shape and size of evergreen rhododendrons allow, you can tie the bushes with elastic strapping.

How can I help you. Broken branches are cut in the spring. Do not rush and cut off slightly broken shoots: you can try to save them. To do this, you need to connect the edges of the fracture, tie up the shoot and fix its position with a support. The strapping and support are left for at least a year.

Ice crust damage to leaves

Evergreens are most often affected. If the crust does not melt for too long, the lower branches, which are in ice captivity, may completely lose their leaves.

How to save. Spruce branches or brushwood are placed under the lower branches of the bushes.

How can I help you. In the spring, severely damaged leaves and shoots are pruned.

Frostbite shoots

The leaves, bark and cambium tissues die, the shoot on the cut is dead - brown. Varieties that are not suitable for this climate zone suffer. At winter-hardy varieties unripe shoots die. As a “growth disease” it occurs in young plants obtained by the meristem method - tissue culture, as well as in the case of late top dressing.

How to save. Choose to land. Top dressing is carried out in doses and only at the beginning of summer. In deciduous species, actively growing blind shoots are pinched at the end of July.

How can I help you. In the spring, frostbitten shoots are cut to healthy wood.

Weak flowering

Varieties rhododendron Caucasian and dense sometimes open part of the buds in the fall. In the spring, they bloom less. Rhododendron Ledebourg and varieties with its participation are trying to bloom in the winter thaws. In this case, nothing can be done.

Weak flowering of the bush with a lack of light, nutrition or moisture

How can I help you. Improve the conditions of detention. Remove faded inflorescences, preventing seeds from setting.

Azalea is very beautiful unusual plant. But at the same time, it is quite gentle, demanding care. That is why the plant is very often prone to various diseases and troubles, including the azalea can dry out or lose all its leaves.

Plant features

It is able to decorate the home with its flowering at any time of the year. Its main advantage is considered to be enough long flowering, which is distinguished by its elegance.

It is an evergreen shrub with many branches. Its leaves are lanceolate, elliptical, ovate, pubescent on both sides. There are hybrids that have semi-double or double bell-shaped flowers, the color of which is quite diverse. The plant can be early flowering, medium or late flowering.

Difficulties of care

The most common problem that can be encountered while growing azaleas at home is the fall of leaves from the bush and its drying. To know how to save the azalea in this case, you need to find out the cause of the problem. She may not be alone.

Causes of leaf fall and solutions

What to do if the azalea dropped all the leaves and withered? Answering this question, first of all it is worth noting that this problem is the most common. The main reason for this phenomenon is the lack of necessary conditions for the normal development of the plant. Azalea requires balance in everything and does not tolerate dry air and high humidity very well, too low temperature and excessively high.

If the azalea is sick, the leaves fall. What to do in such a situation? Everything is quite simple. It is necessary to carefully control the humidity in the room. It is recommended to do this with the help of a pallet in which you can place a certain amount of wet expanded clay and peat. In addition, you need to spray the surface of the leaves several times a day, but this is strictly prohibited during the flowering period. It is also possible to lower the plant pot itself into a container of water. room temperature. This is to allow the overdried soil to absorb required amount water for the normal development of the shrub.

How to save the azalea in this situation? To reduce the risk of such a nuisance, you need to use only the water that has previously settled for at least three days. Use is also allowed.

Another reason for yellowing and further falling of leaves and buds can be spider mite. A thin cobweb, which is located in the internodes of the stems, will tell you about his presence. To eliminate the problem, the plant must be sprayed frequently and abundantly; during flowering, use a soap solution or special chemicals.

Causes of yellowing leaves. Troubleshooting

The main reasons for the appearance yellow leaves and their further fall are two:

The development of chlorosis, which is a consequence of the increased content of calcium in the soil. You will see that the azalea is suffering - the leaves are falling. What to do to solve this problem? Everything is quite simple: you just need to slightly acidify the water with which you water the azalea. At the same time, do not forget about the comfortable temperature of the water, which should be about 15-16 ° C.
The presence of a thyroid gland on the surface of the plant. This insect leaves brown plaques on the leaves. In the future, this leads to the fact that the color of the leaves fades, a sticky coating forms, shine, and soon the leaf falls off. The way to deal with insects depends on the stage of the lesion. At the initial stage, the azalea needs to be treated with a soapy solution. For more complex lesions, the use of special chemicals is required.

Reasons why azalea leaves dry. Methods for dealing with the problem

What to do if azalea leaves fall and dry? First you need to find out the reason for this phenomenon. There may be several.

One of the reasons why azalea leaves dry and curl up may be azalea moth. It will not be difficult to detect it, since this insect is quite large, has the shape of a caterpillar. To get rid of the misfortune, you need to manually collect all the insects and then treat the plant with special chemicals.

If the azalea is not completely dry, how to sleep the plant? The situation when the leaves do not fall, but simply dry, may indicate overdry air. The reason for this may be the high temperature in the room or the location of the flower pot in a sunny place. However, there is no need to panic if some leaves withered immediately after flowering. This process is quite natural. If the leaves dry during flowering, then most likely the plant lacks moisture.

Is there a solution to the problem when the azalea withered? How to save her? You can solve the problem of dry leaves by increasing the amount of watering. You can use thawed or rain water. Once a month, it is recommended to water the plants with acidified water (add 5 drops of lemon juice to 1 liter of water).

Why did the azalea shed its leaves and wither?

When growing azalea, it should be understood that twigs that dry out are not the norm, but lead to the death of the plant. In order to know how to reanimate an azalea, you need to find out the cause.

There may be several. Among them are:

disease damage;
possible stressful situations;
transplanting during the period of active flowering;
insufficient level of feeding;
insufficient lighting;
possible insect infestation.

If yours is, it will help you find out detailed instructions.

How to revive an azalea?

First of all, you need to prepare the following ingredients:

the soil;
some cold water;
a little boric acid, can be replaced with citric acid;
pine needles;
ash, activated carbon is also suitable;
sand;
means "Zircon".

If you don't know how to revive an azalea, just follow these steps.

First of all, the plant must be freed from the pot and placed with its roots in the cooked cold water. Rinse roots thoroughly and gently. After complete cleansing of the substrate, lower the azalea under running water, which should be cool.

After cleaning, the azalea must be planted in new ground. It is better if you use a special substrate for flowers. Leave the plant to spend the night and in the morning cover the ground with ice, while watering is very necessary. cold water. You should also avoid direct contact with the plant, especially in summer.

Prepare water in a special way: let it stand for two days, then add a few drops of boric or citric acid, you can also use the Zircon preparation. Water the plant with this solution for several days in a row until the desired result.

At the end, the pot with the transplanted plant must be placed on a surface covered with wet expanded clay, in a draft. In the summer you can even put it in the refrigerator. Water the plant every other day with very cold water. It is recommended to lay pine needles on the top layer in the pot, but this is an optional condition.

Preventive measures

It is much easier to prevent a problem than to solve it. That is why you will keep the plant healthy for a long time if you take into account the peculiarities of caring for the azalea.

The main components of caring for this flower are: watering, top dressing, temperature and light conditions. The plant should not be waterlogged, as this can lead to its death. You can use water for irrigation at room temperature or 2-3 degrees warmer. Once a month, you need to use acidified water or a liquid with the addition of boric acid.

If necessary, excess stems should be removed. The plant needs to be fed in the autumn, summer and spring periods.

Very often you can see that after flowering, the azalea withered. How to save her in such a situation? To do this, the pot with the plant must be placed in cool place. And at the moment when it begins its active growth, transplant into a new prepared substrate.

Azalea is famous for its whimsical and fastidiousness. However, her beauty is worth the time and effort that you spend on care. And even if your azalea has dried up, you now know how to save it.

Plants known as rhododendrons are unique shrubs. Azaleas and rhododendrons bloom in May and June, so they are the best choice for people who expect beautiful and impressive flowers at the beginning of summer. Rhododendrons are evergreen shrubs, while azaleas shed their leaves in autumn. They also vary in height and appearance colors that are exceptionally good.

Rhododendron - is a species of shrubs belonging to the heather family ( Ericaceae). In the natural environment plants of the genus Rhododendron found mainly in the mountain forests of Asia and North and Central America. They inhabit places with high humidity. Azaleas have soft, slightly hairy leaves that fall off in the winter, making them more frost hardy. The "correct" azaleas are evergreen, and in winter they cannot tolerate the influence of cold, drying winds.
Both species plant the ground between April and mid-September. They are bought in containers. Before we make a decision on a particular purchase, it is worth checking if the substrate in the container is sufficiently moist. If it turns out to be too dry, it may mean that the plant has dead roots because they do not have enough moisture. You also need to carefully examine the leaves and shoots. They should be free from discoloration, spots, cavities, or other worrying changes that may indicate rhododendron disease.

Planting a rhododendron

In general, rhododendrons will thrive best in areas of the country where winters are relatively mild and wet. In the garden itself, rhododendrons will be comfortable in partial shade or a shady place that is protected from the wind. The best position is near the water, where the humidity is high. In turn, azaleas are planted in a well-lit or slightly shaded area.

Rhododendrons need an acidic substrate and fertile soil.

Unfortunately, this soil is not often found in gardens, so it must be properly prepared before planting. In a hole 50 cm deep and about 1 meter wide, pour 10 to 20 centimeters of drainage in the form of gravel or mulch. Then a layer of peat mixture, composted bark and compost in equal proportions. After planting the shrub, the top layer of the substrate is additionally mulched with a five-centimeter layer of bark. This will ensure sufficient soil moisture and minimize the development of weeds.

well-prepared soil and proper fit will create ideal starting conditions for the growth of rhododendrons.

We plant correctly

1. In a healthy seedling, thin white roots penetrate the earthen ball. For their further normal development, loose soil enriched with peat is necessary.
2. Before planting, submerge the root ball in water and keep it there until bubbling stops.

3. The planting hole should be 2 times wider than the root ball of the plant. Loosen the soil in the planting hole with garden forks.
4. To fill it, a mixture of garden soil with peat (50% each) or a special soil for rhododendrons is suitable.

5. Important: do not plant rhododendrons too deep. The upper part of the coma should be at the level of the soil surface.
6. Mulch the soil around the plant with a layer of 1 to 3-5 cm. Use for this purpose compost from bark or pine needles aged for at least six months, as well as well-rotted oak or beech leaves.

7. After planting, fertilize the plants. The ideal top dressing is a mixture of horn shavings and mineral fertilizers or special fertilizers for rhododendrons. Spread the fertilizer evenly over the surface of the earth and water the seedling well. If you plant a plant in the fall, do not feed it, but wait until spring with this.
8. Water the rhododendron thoroughly, but do not overdo it (so that there is no moisture stagnation).

Watering is important not only after planting, but also in the following months, until the root system of the bush is strengthened. Rhododendron planted in dry places should be watered more often. Watering is also necessary after each fertilization.

Substrates, fertilizers and mulch

For health and abundant flowering of rhododendrons, loose, humus-rich soil is necessary. You can improve your garden's clay or calcareous soil by adding peat and humus to it. Special soils for rhododendrons or peat substrates are ideal. Remember that fertilizers must meet all the needs of rhododendrons. Fertilizers vary in quality, so we advise you to buy products well-known manufacturers. But as a mulch it is good to use pine bark.

Lime is no longer scary

Limestone gardeners can now grow rhododendrons too. As a result of many years of work, breeders managed to obtain a rootstock that is tolerant to lime (INCARHO rhododendrons). Many popular varieties of rhododendrons are grafted onto this stock. True, they are not entirely immune to lime, but show a certain tolerance for it. Experts recommend these varieties for gardens with soils with a pH of 5.5 to 7.0.

Outdoor rhododendron care

The soil under the rhododendrons can not be dug up, so as not to damage the roots. Loosening with a thin hoe is allowed. However, it is necessary to regularly remove weeds before they reach large sizes, as removing large weeds can also damage the small roots of the rhododendron.

Rhododendrons need to be fed with special preparations that can be purchased at garden stores. Delivery nutrients should take place in spring and early summer. However, be careful not to extend this period as the plants will not have time to prepare for winter.

Fertilizers for growth and abundant flowering

Rhododendrons growing near deciduous trees do not need additional fertilizer, its function is performed by the foliage that falls every year. However, in most gardens, rhododendrons still need regular fertilizing with mineral fertilizers, especially if the bushes are still young.

The first time to fertilize rhododendrons is best in April-May, when the plants are actively growing.
The second - more important - feeding is done after the flowering of rhododendrons, when new shoots appear on the plants (usually in June-July).

Indicative figures: for a plant with a height and width of 40 cm, about 15-20 g (half a tablespoon) of fertilizers are required in spring and summer, for a plant with a height of 150 cm, respectively, 80-100 g.

Do not use liquid fertilizers, better use granular, long-acting or specially formulated fertilizers for rhododendrons.

Careful rhododendron care also includes an annual pH test of the substrate. If necessary, we also mulch the substrate with a mixture of bark and acid peat.
After the rhododendron fades, it begins the process of seed formation. Gently pinch off the buds as soon as they wilt. Thanks to this, the plant will not waste energy on seed maturation, but will save energy for the formation of new shoots and flowers next year. In addition, rhododendron bushes take on a more well-groomed appearance.

pruning

Can you prune rhododendrons?

It is better not to prune at all - rhododendrons look more picturesque over the years

It is better not to cut them at all - rhododendrons look more picturesque over the years. If you have to cut a bush that is too tall, then it will soon give new shoots even on old lignified branches (see photo). Note, however, that these slow-growing shrubs will take several years to grow back to their original height.

In the spring, dried and frozen shoots should be cut. Young plants can also be stimulated at this time by lightly pruning them. Old bushes that have lost a lot of lower leaves and look ugly should be rejuvenated by cutting out all shoots, even thick ones. After pruning the branches in a few weeks, many young branches will grow from the dormant buds. If you're unsure if a bush is strong enough to withstand such a drastic cut, you can rejuvenate half of the bush in the spring and the rest next year.

Shelter from frost and wind

Hanging leaves are not a sign of frost damage.

Rhododendrons grow well in temperate climates with warm winters and high humidity. In such conditions, even in the cold season, metabolism occurs in their evergreen leaves. But the cold winters of Central Europe are not entirely suitable for rhododendrons - on sunny days, the process of photosynthesis begins in the leaves, and the roots cannot absorb enough water from the frozen soil for metabolism, and the leaves begin to dry out. Therefore, for rhododendrons, the winter sun at sub-zero temperatures is more dangerous than frost itself.

For sensitive varieties and standard plants, it is advisable to use shelters that create shade. They protect plants from the wind and, by creating shade, prevent dehydration of the leaves. Such shelters are best made from breathable materials, such as agrofibre, otherwise mold may appear under them. Dehydration is especially dangerous for container rhododendrons, so they should be watered abundantly in winter.

Rhododendrons growing in the shade, for example under the crowns of trees, usually do not need to be covered for the winter.
Hanging leaves are not a sign of frost damage, but the plant's natural reaction to it. The tent will protect from the wind, cold and winter sun, which can dry the leaves during frost on the ground. In standard plants, both the crown and the trunk should be covered for the winter.
Small "LEGS" under the tubs and pots will ensure that excess water drains.

Optimal watering

Rainwater is ideal for irrigation, as it does not contain lime.

Rhododendrons prefer evenly moist soil. They are equally sensitive to both drying and waterlogging. When watering, you need to know when to stop: a large amount of water washes out nutrients and leads to rotting of the roots, with insufficient watering, the bushes wither and dry out. If the leaves drop during the day from the heat, then this is normal, the plants usually recover overnight. For irrigation, it is better to use rainwater, which, unlike tap water, does not contain lime. A layer of mulch prevents water from evaporating and retains moisture in the soil. The same function is performed by ground cover plants that create a favorable microclimate. For dry soil, computer-controlled drip irrigation is suitable, evenly moistening the soil.

Important: evergreen rhododendrons should be watered in winter.

Reproduction by layering

After flowering has ended, lightly cut the bark of a branch close to the ground under the whorl of leaves. Bend the branch so that its notch down can be placed in a hole filled with humus to a depth of 5 cm. Carefully fix the branch with a hook and make a support. The next spring, rooted cuttings can be separated with a shovel and transplanted to a permanent place in the garden. After planting, do not forget to water the young plant well.

Caring for rhododendron after flowering

1. Removing faded flowers

Removing faded flowers is essential for rhododendrons to form new flower buds and leaves the following season. Faded inflorescences are removed in summer, when rhododendrons finish their flowering period, leaving new leaf buds underneath. It is better to cut off the inflorescences manually (not with scissors). Thanks to this treatment, the seed production process is not carried out, and nutrients can be used by the plant for growth, development and creation of new buds. You can also cut dead, dry shoots.

2. Removing fallen flowers and leaves

It is necessary to carefully remove fallen flowers and leaves from under the bush. Especially if they are affected by lesions, they must be removed and burned. The litter will rot, providing nutrients for the development of fungal diseases.

3. Fertilizing rhododendrons after flowering

Rhododendron after flowering feels a lack of nutrients that were used in the flowering process. Use in summer and autumn phosphorus-potassium fertilizer. During this period, plants do not need much nitrogen. Mineral fertilizers - potassium sulfate and superphosphate or available ready-made fertilizers for rhododendrons, containing all the necessary ingredients that also affect soil acidification. In addition, foliar fertilizers are used that contain trace elements such as iron and magnesium, which affect the intense color of the leaves. Fertilizers should be applied no more than the recommended doses.

Providing nutrients will allow the rhododendrons to set up many new flower buds.

4. Watering rhododendrons after flowering

With excess water, plants are exposed to fungal diseases. However, if there is a drought, with lots of sunshine and hot weather, which often happens during the summer months, after the rhododendron has bloomed, the bushes should be watered. In particular, plants that grow in light and permeable soils require watering. In other periods, rainfall water is sufficient and most healthy for plants. Plants need more water before the onset of winter. With big frosts, they will no longer be able to collect it, and this is necessary for the proper development of the leaves. In the absence of water, the leaves wilt and turn brown. Therefore, rhododendrons should be watered abundantly just before the onset of frost.

5. Shelter of rhododendrons for the winter

Most varieties of rhododendrons are resistant to frost, even down to -30 ° C. Some varieties are less frost resistant (down to -20 ° C). The best cover for winter is snow, but it is not always present. It is advisable to cover young rhododendrons planted in the current year. You can use spruce branches, straw mats or agrofibre. Young and older shrubs are well mulched for the winter with pine bark, which additionally acidifies the soil. Freezing of the soil and loss of water is less. Roots are less vulnerable to frost damage. Rhododendrons that survive the winter in good condition will bloom again a year later.

Diseases and pests of rhododendron

Why do rhododendrons get sick? Rhododendrons have fairly high cultivation requirements and our climate is not conducive to these plants.

Rhododendrons can be affected different types mushrooms. As a result, the leaves turn brown at the edges or at the tips, dry out and eventually fall off. In addition, shapeless heels often appear on the leaves. With the help of fungicides, these symptoms can be removed, but the cause of their appearance - the unfavorable living conditions of the plant - will remain. Sometimes just good feeding leads to the recovery of rhododendrons. Also control the acidity of the soil.

Kidney death

Brown buds with black down indicate fungal infection. Such kidneys should be removed.

Unfortunately, a common disease of rhododendrons is the death of the kidneys. It is caused by a fungus carried by rhododendron cicadas. Buds affected by the fungus turn brown and fall off. It is impossible to destroy the fungus, but, fortunately, it does not spread to other parts of the plant. Cut off and destroy the affected kidneys.

To check if there are insects on the rhododendron, a yellow sticky paper (photo) attached to a plant branch will help.

To prevent damage to the kidneys by the fungus, you must first fight the cicadas: inspect the rhododendron, usually these insects sit on the back of the leaves.
It is best to destroy cicadas in the early morning, when the insects are still inactive. Treat the leaves with an insecticide: you need to spray the plants immediately after the appearance of cicadas in mid-May, if necessary, repeat the procedure after 2 weeks.
Green-yellow cicadas about one centimeter long sit mainly on the underside of the leaves. Small dots on the leaves are traces of their vital activity - give out the presence of "uninvited guests".

Wasting, chlorosis

With chlorosis (exhaustion), the leaves of the rhododendron turn yellow, while the veins remain green. This disease occurs most often due to insufficiently acidic or very dense soil that does not allow air to pass through.
Most often, chlorosis begins a few years after planting, when the roots extend beyond the planting hole and enter the calcareous soil. Help: transplant the plant to more appropriate place or acidify the soil underneath by lowering the pH.

frost

Even though rhododendrons have survived the low temperatures in winter relatively well, they are susceptible to late spring frosts. A light frost in May can severely damage the young leaves and flower buds of the plant that have already appeared. If new shoots come out of the spare buds, the plant will not die, but it is better to remove the darkened branches of the rhododendron.

Ravenous weevil

Weevil is a dangerous pest

Semicircular eroded places on the sides of the leaves are a sign of the appearance of a pest.

More dangerous than the beetles themselves are their larvae, which eat the roots of shrubs. They are yellowish white in color with a brown head.

If the lower old leaves of rhododendrons have turned completely yellow (unlike those affected by chlorosis) and are gradually falling off, the plant is most likely lacking nitrogen. It is one of the main plant nutrients, and flowering rhododendrons especially need it. Help: immediately apply complex fertilizers to the soil. And best of all, feed the bushes every spring with horn shavings - this will prevent a lack of nitrogen.

Rhododendrons, like any other plants, are affected by diseases and pests. Susceptibility to various diseases and pests mainly depends on the type and variety of the plant. Long-term practice shows that evergreen rhododendrons growing in open sunny areas are more susceptible to diseases and pests than those that grow in light partial shade. Depleted specimens are usually more susceptible to diseases and pests than well. developed plants. The main thing in protecting rhododendrons from pests and diseases is to create for them optimal conditions growth and development. Compliance with the rules of agricultural technology and the choice of planting site corresponding to the requirements of the plant are essential. With proper agricultural technology for growing rhododendrons in culture, plants are only slightly damaged.

Diseases

Fungal diseases on seedlings of rhododendrons appear due to poor soil aeration, which occurs with excessive watering. Often this is one of the reasons for the mass death of seedlings. Plants infected with fungi should be regularly sprayed with a solution of Bordeaux mixture. Sick and weakened plants, as well as stumps, must be burned in order to eliminate the foci of the spread of fungal diseases.

Tracheomycosis wilt of rhododendron

Symptoms: the roots turn brown and rot, the fungus penetrates into vascular system plants and fills it, blocking the movement of nutrients. Leaves, starting from the upper parts of the shoots, gradually lose turgor, turn brown and dry. The leaves fall along with the petioles, and a grayish-white mycelium begins to spread from the vessels of the stem along the bark. The infection persists in plant debris and infected plants.

Control measures: timely burning of dead plants along with the roots. In industrial cultivation - preventive spraying of plants and watering the root zone with a 0.2% solution of foundationol.

Phytophthora root rot

Pathogen: Phytophthora cinnamomi fungus. Causes: drift from the nursery with acquired plants, soiling and poor drainage root zone. Symptoms: first, the leaves begin to wilt, often not on the whole plant, but on individual branches. At the same time, this wilting is not associated with overdrying; wilted leaves do not restore turgor at night or early in the morning. In the region of the root neck - lesions under the bark. Further - the branch turns yellow, then the whole plant. Roots turn brown, rot, soak. Large brown spreading spots appear on the root neck and the base of the stems, the wood rots. Dense dark gray sporulation of the fungus develops on the spots. Affected plants wither and dry out. The infection persists in the soil and on plant debris.

Bacterial root cancer

The causative agent is the bacterium Agrobacterium tumefaciens, a gram-negative, obligately aerobic rod-shaped soil bacterium of the genus Agrobacterium. Able to transform plant cells using a special plasmid. Phytopathogen, causes the formation of crown galls in plants, conditional pathogenicity is also known in people suffering from immunodeficiency diseases. Chemoorganoheterotroph, obligate aerobe.

Symptoms: large, rounded outgrowths form on the roots and root neck, which gradually darken and become hard. Plants slow down growth and bloom poorly. Over time, the growths and the root neck rot and the plant dies. The infection persists in plant debris, often spreading with planting material.

Control measures: regularly spray weakly affected plants with a solution of Bordeaux mixture or its substitutes; severely affected plants are burned along with the roots.

Gray rot of rhododendron

Symptoms: blurry brown spots without bordering appear on leaves, stems, buds and petals, the surface of which quickly dries and cracks. In humid weather, all necrotic parts are covered with a fluffy smoky-gray coating of sporulation. Over time, brown rounded sclerotia form in the drying mycelium.

Control measures: pruning the affected parts of plants. In industrial cultivation - preventive spraying of plants and watering the root zone with a 0.2% solution of foundationol.

Rot of seedlings and young seedlings of rhododendron

Often, when propagating by seeds and cuttings, one has to observe a sudden mass wilting of rhododendrons, their decay and death. The causative agents of this disease are fungi of the following genera: Rhyzoctonia, Pythium and Botrytis. Affected seedlings fall sideways and die, white hyphae of fungi or brownish mold are visible on the leaves. Pale, cobweb-like threads appear on the surface of the substrate. Fungi usually develop if the substrate is fresh, not yet decomposed, or if the crops are watered with fungus-infected water. Too much planting density, excessive humidity in greenhouses and insufficient air exchange increase the likelihood of disease.

Control measures: Beginning seedlings to die should be sprinkled with finely ground charcoal to stop the spread of the disease. In addition, the disease can be instantly eliminated by sprinkling the affected areas with foundation powder. In order to prevent young shoots and seedlings, it is desirable to spray with a 0.2% suspension of foundationol. Captan and TMTD can be used to combat this disease.

Rhododendron bud rot

Pathogen: fungus Sporocybe azaleae (syn.: Pycnosteanus azaleae) which is spread by the cicada Graphocephala coccinea. The disease was first detected on rhododendrons in the United States. The disease is typical for the largest rhododendrons (Rhododendron maximum L.) and Katevbinsky (Rhododendron catawbiense Michx.). Buds affected by this disease turn brown and die. Mushroom from buds can grow into branches and lead to their death.

Control measures: during the growing season, plants should be sprayed regularly (every 2-3 weeks) with copper-containing preparations.

The death of the shoots of rhododendron

Plants planted in full shade are most susceptible to this disease.

The causative agent is the fungus Phytophtora cactorum Leb. Symptoms: in the affected plants, the apical buds do not bloom, they turn brown, and then completely die off. The shoots also dry out at first, and later die off. Mature leaves curl up, turn brown and dry. Severely affected plants die.

The causative agent is the fungus Physalospora rhododendri. This fungus also infects lilacs. Symptoms: in diseased plants, on some shoots, the leaves turn brown, dry out, and then the entire shoot dies. The disease has been noted in Latvia.

Control measures: affected leaves and shoots are burned. After flowering, rhododendrons are regularly sprayed with copper-containing preparations. Spraying is done every 10-14 days.

Rhododendron root rot

The causative agent is the fungus Phytophtora cinnamoni Rands. This fungus most often damages the roots and base of the stem. Symptoms: on individual shoots or on the whole plant they wither, and then all the leaves dry up without externally noticeable reasons. The apical buds turn brown and die. Cross sections of the shoots show that the cambium layer is brown. The roots turn brown and rot, the plant dies. This disease mainly affects rhododendrons growing on insufficiently acidic, highly moist soils. Most often, young and oppressed plants suffer. Plants are infected through the root system or through damage to the bark and roots.

Control measures: affected shoots or the entire plant is burned. To prevent the disease, it is necessary to maintain the acidity of the soil corresponding to the requirements of the plant species or variety and observe the correct irrigation regime.

Dry white rot of the root neck of rhododendron

The causative agent is the fungus Armillaria mellea (real honey agaric).

Symptoms: in diseased plants, the root neck is entwined with a grayish-white ring - mycelium. This disease usually affects those plants that have damage to the root collar. The plant affected by the fungus dies. Strongly growing rhododendrons do not get sick with dry rot of the root neck.

Control measures: affected plants are dug up and burned. Plants near which the disease is found should be transplanted so that the root neck is not covered by mulch (it must be dry).

Wax disease of rhododendron, or swelling of the leaves of rhododendron

Symptoms: there is a slight deformation and thickening of the leaves. Large, rounded or oblong spots of red or red-brown color appear on them. A dense waxy coating of sporulation develops on the surface of necrosis. Over time, the spots dry out and crack. Affected plants lose their decorative effect and bloom weakly. This disease usually affects alpine views rhododendrons - Rhododendron ferrugineum L., Rhododendron hirsutum L. and others. With the defeat of rhododendrons by the fungus Exobasidium rhododendri, a change occurs in the metabolism of amino acids.

Exobasidium vaccinii - the causative agent of a very common disease of lingonberry leaves, causes the formation of white cushion-like growths on young leaves of evergreen rhododendrons (Rhododendron maximum L., Rhododendron catawbiense Michx.) and deciduous rhododendrons in their natural places of growth.

Exobasidium burtii forms characteristic spots on the leaves, which at first are small, round, and later, increasing in size, acquire an indefinite shape. White spores are visible on the underside of the leaf. This disease usually affects Rhododendron ponticum L. and Rhododendron luteum Sweet. As of 1981, this disease was not observed in Latvia.

Exobasidium vaccinii-uliginosi Bond., the causative agent of a very common blueberry leaf disease, causes the formation of the so-called "witch's broom" in the Carolina rhododendron. The leaves turn yellow-brown, their underside is covered with powdery coating. A year later, the affected leaves die off. As of 1981, this disease was not observed in Latvia.

Measures to combat diseases caused by representatives of the genus Exobasidium: pruning of the affected parts of plants, spring spraying with a solution of Bordeaux liquid, its substitutes or camulus.

Exobasidium japonicum attacks leaves and shoot tips. Affected plants develop abnormally thick, large, pale green leaves covered with a chalk-white coating. These leaves quickly shrivel, grow moldy and dry out. On the annual plants the fungus is less common than on older ones. Susceptibility to this disease largely depends on the type and variety of rhododendrons. As of 1981, this disease was not observed in Latvia.

Pestalocium blotch of rhododendron

Pathogen: fungus Pestalotiopsis sydowiana (syn.: Pestalotia macrotricha Kleb., Pestalotia rhododendri). Leaves and stems are affected. Small brown spots appear on the leaves irregular shape with a thin brown border. The spots are often scattered along the edges of the leaf blade, which turns yellow and dries prematurely. Gray sporulation pads form on the spots. The spots on the stems are large, depressed, elongated. The surface of the spots dries up and brightens, numerous small gray pads of sporulation of the fungus are formed. Affected shoots gradually dry out.

Anthracnose blotch of rhododendron

Pathogen: fungus Gloeosporium rhododendri. On the upper part of the leaves, marginal necrosis appears in the form of brown spots of irregular shape. The leaves gradually dry up. On the surface of the spots, sporulation is formed in the form of numerous rounded fruiting bodies. dark color. If the infection continues to develop, the stems are also affected, which dry out over time. This disease is widespread in Holland and England on young seedlings of the Pontian rhododendron.

Control measures: pruning of the affected parts of plants, spring spraying with a solution of Bordeaux liquid, its substitutes or camulus.

Septoria blotch of rhododendron, or azalea septoria, or small leaf spot

Pathogen: mushroom Septoria azaleae Voglino. Symptoms are described by different authors with slight differences.

1. Small rounded reddish spots appear on the leaves, gradually turning white in the center. Over time, dotted black fruiting bodies of the overwintering stage of the fungus form on the surface of the spots. The leaves turn yellow and gradually dry out.

2. As a rule, greenhouse plants are susceptible to the disease. In countries where rhododendrons are cultivated very widely, this fungus is also found on deciduous rhododendrons in open ground. Yellowish, red-yellowish, later yellowish-gray spots of irregular shape appear on the leaves of plants. By autumn, they become dark brown in the middle, and sometimes even brownish black. At first, the spots appear in the middle of the leaf blade, gradually increase and, having reached the large veins, stop. The fungus grows into all leaf tissues, the leaves die and fall prematurely, so that the plant becomes completely naked. As a result of falling leaves in plants, all physiological processes are disturbed, flower buds are not normally laid. On the spots one can see small, black, dot-like receptacles of spores - pycnidia, immersed in leaf tissues.

Control measures: pruning of the affected parts of plants, spring spraying with a solution of Bordeaux liquid, its substitutes or camulus. If the air is excessively humid, do not spray plants with preparations containing copper, as this leads to burns of leaves and young shoots. Preparations containing copper are used only at normal air humidity and at a sufficiently high temperature. You can spray only those plants whose leaves have fully grown and developed.

Phyllostic blotch of rhododendron

Mushroom Phyllosticta concentrica Sacc. (syn.: Phyllosticta maxima Ellis & Everh.). Symptoms are described by different authors with slight differences.

1. Large rounded spots with a reddish border appear on the leaves.

2. The spots are indistinct, irregular, dark brown or ash gray, with dark edges. Localized along the edges or at the ends of the leaves. Black balls - sporangia - fall out of the spots. In the vast majority of affected leaves die, and the process begins at the tips of the leaves. Similar spots are formed by the fungus Phyllosticta saccordoi.

Mushroom Phyllosticta rhododendricola.

Symptoms: the appearance on the leaves of reddish rounded spots with a thin brown border.

In the future, the affected areas brighten, crack and fall out. Black dotted bodies of the hibernating stage are formed on the necrotic tissue.

Control measures: pruning of the affected parts of plants, spring spraying with a solution of Bordeaux liquid, its substitutes or camulus.

cercosporosis

Pathogen: Cercospora rhododendri Ferraris.

Symptoms: Irregular, angular, dark brown spots with reddish edges appear on the leaves, especially noticeable on the underside of the leaf. In conditions of high humidity, the upper side of the leaf blade is covered with a gray coating of sporulation. V more leaves of the lower tiers are affected. The causative agent is widespread in the United States, especially on Pontic rhododendron and varieties based on this species. Another mushroom of the same genus, Cercospora handelii Bubak, is also dangerous.

Rhododendron rust

The causative agent is the fungus Chrysomyxa rhododendri D. C. Most often found on small-leaved species and species from the Osmothamnus subgenus - Rhododendron parvifolium, Rhododendron adamsii, Rhododendron dauricum L., Rhododendron ferrugineum L., Rhododendron kotschyi, and others.

Symptoms: in autumn, yellow, red or brown dust-like swellings - sporangia appear on the underside of the leaves of affected plants. Severely infected plants shed their leaves prematurely. In spring, dark red pads are visible on the leaves - the winter form of the fungus.

Control measures: Affected leaves are collected and burned. Sick plants are sprayed with copper-containing preparations. In the early stages of this disease, spraying plants with Bordeaux mixture helps.

Mosaic of rhododendron

The causative agent is the Rhododendron mosaic virus. Symptoms are described by different authors with slight differences.

1. Small mosaic yellow spots and swellings appear on the leaves. Plants are stunted and bloom poorly. The leaves turn yellow, but they retain patches in the form of alternating green and brown spots.

2. Leaves become rough, calloused and ugly. Calluses are usually a normal green color, with the rest of the leaf turning greenish yellow. The light part of the leaf blade is much thinner than in places where there are calluses. Venation on calluses is less noticeable.

Control measures: pruning of leaves and branches, culling of heavily affected plants. Mosaic virus is carried by aphids, bedbugs and other insects.

Pests

Furrowed weevil (Otiorrhynchus sulcatus)

Adults are black, 8-10 mm long, not flying, with an elongated head extended forward, at the end of which there are mouthparts. Elytra with deep punctate beards. The larvae are white, with a brown head, legless, curved, up to 12 mm long. The larvae live from 2 to 12 months, then pupate, and after 20 days the pupa turns into an adult beetle. Females live 5-12 months, laying 100 to 1000 eggs in their lifetime. Eggs are laid in groups in the soil, where after 2-3 weeks the larvae emerge from them and immediately start feeding.

The nature of the lesion. Along the edges of the leaves, characteristic eaten away areas are observed. If the damage is inflicted by larvae living in the soil, then the plant suddenly withers and dies.

Control measures: spraying with decis, splender, actellik, or spark.

Common spider mite (Tetranychus urticae)

Almost invisible, since its dimensions are 0.25-0.43 mm. At the larval stage of development, they are transparent, colored from light green to greenish brown in color with two distinct, large dark spots on the sides, which are formed by transparent blind sacs of the midgut. From late summer until the following spring, overwintering females are orange-red to bright red. In contrast to the six-legged first larval phase, all adult ticks have 8 legs.

Damaged leaves turn yellow, deform, turn brown and dry. Up to 10 generations of ticks develop during the growing season.

Control measures: spraying plants with fitoverm, fufanon, karbofos, actellik, or colloidal sulfur.

Acacia false shield

Acacia false scale, or acacia scale, or hazel scale, or acacia scale insect (Parthenolecanium corni). It is currently ubiquitous. In the north, the range reaches Leningrad region. Sexual dimorphism is pronounced. The body length of females is from 3 to 6.5 mm, width - 2.4 mm, height - 4 mm. There are no wings. Body oval or broadly oval, sometimes almost round, no segmentation. The shape, color and size of the body of the female vary depending on the type of host plant. Young females with a delicate, not very convex body, more oval in shape, light brown, with two black stripes and longitudinal black stripes extending from them. Dead - shiny, painted in dark yellow, brown or dark brown. The body length of males is 1.4-1.6 mm. The body is thin, elongated, with a clear segmentation into the chest, head and abdomen. The head is black with three pairs of simple eyes. Abdomen and thorax red-brown, covered with white waxy coating. Ten-segmented antennae and legs are yellow. At the top of the abdomen there are two caudal filaments, 2-2.5 times longer than the body size. Larvae of the first age (tramps) are 0.36 mm long. The body is flat, elongated-oval, slightly narrowed towards the posterior end. The color of the covers is cream or light yellow. In the second age, the larvae of heterosexual individuals differ from each other in body shape. The nymphal stage of development is observed only in male larvae. Nymphs are dark brown in color, have well-developed rudiments of wings, legs and proboscis. Reproduction in acacia false scales is often parthenogenetic, sometimes bisexual in the south. The larvae hibernate. In the northern part of the range, one generation develops per year, in the southern part - two or three.

Insects pierce the bark of the plant with their proboscis and attach tightly to the branches. Damaged plants weaken, lose their decorative effect and gradually dry out.

Control measures: timely spraying of plants with organophosphorus compounds, neonicotinoids, pyrethroids, fitoverm, fufanon, karbofos, actellik.

Thrips tobacco (Thrips tabaci)

In Russia, it is ubiquitous. Polyphagous, damages about 400 plant species in open and closed ground. The coloration of the female is variable, from light yellow to brown, often more or less yellow, sometimes strongly darkened. Body length 0.8-1.0 mm. The male is smaller and lighter, the chest is bright yellow. Body length 0.7-0.75 mm. The larva, 0.8-0.9 mm long, is very mobile, two pairs of wings are surrounded by a fringe of cilia, the body color is variable - from yellow to almost black. Adults overwinter in top layer soil at a depth of 5-7 cm or in plant debris. They emerge after wintering in the first half of April, feed and lay eggs at first on weeds. One female during her life (20-25 days) lays about 100 eggs in the leaf tissue, and their fertility largely depends on the type of host plant. Then the females fly to cultivated vegetation. Is a distributor of viruses. On rhododendrons, buds are damaged, which, if severely damaged, do not open, turn yellow and fall off.

Control measures: timely spraying of plants with organophosphorus compounds, neonicotinoids, pyrethroids, fitoverm, fufanon, karbofos, actellik, actara.

Rhododendron mite or American azalea bug (Stephanitis rhododendri)

It occurs on the Katevbinsky rhododendron, Smirnov's, Ungern's rhododendron and other species and varieties that have felt pubescence on the underside of the leaf.

Adult size is about 3.6 mm. Wings are colorless, reticulate with a sheen. Bedbug larvae reach a length of 0.7 to 2.2 mm, they do not fly, they are yellow in color with dark spots and hairy outgrowths from the sides.

Symptoms: the leaves turn yellow, and black spots appear in their lower part, resembling resin. Damage contributes to curling and drying of the leaves. The bug appears in summer, spreads along with peat and pine needles along with the substrate.

With minor damage, you can collect pests by hand. In addition, in late May - early June, plants should be sprayed with nicotine and soap, or a flavored pyrethrum extract. In case of severe damage, pruning of shoots is recommended.

Greenhouse whitefly (Trialeurodes vaporariorum)

Tropical species. Introduced to all continents. It is noted near greenhouse plants, where the pest persists all year round. The greenhouse whitefly is known as a carrier of many viral infections.

Signs of damage: small white insects are visible on the underside of the leaves. The body of the adult is light yellow, the wings are white, without spots. The size of the female is 1.1 mm, the male is 0.9 mm. In GBS, it is quite often noted on large-leaved rhododendrons (Caucasian, Pontic). To combat the greenhouse whitefly, pesticides are chosen that are of little danger to pollinating insects and entomophages. V last years neonicotinoids are becoming more and more popular.

Whitefly rhododendron, or white rhododendron fly (Dialeurodes chittendeni)

V GBS are found mainly on large-leaved rhododendrons: Caucasian, Pontic and Ketevbinsky and their varieties and hybrids. Spraying leaves from below with nicotine and oil emulsion in spring and autumn is recognized as the most effective. For preventive purposes, it is recommended to spray adult flies with nicotine dust during the summer. Affected leaves should be cut off and burned.

gastropods

Leaves, buds and young shoots of rhododendrons damage Helix snails and slugs. Control measures: manual collection of molluscs, use of molluscicides.

crows

In GBS in early spring, the facts of pecking of the buds of rhododendrons by crows were noted, Smirnov's rhododendron most often suffers.

The question "How to reanimate an azalea?" most often occur in people who are unprepared for the appearance of this flower in the house - they usually give it in an attempt to please the hostess. At first everyone admires flowering plant, and later unrest begins due to yellowing, blackening or drying of the leaves, as well as falling flowers. In such cases, it is urgent to decide how to save the dying azalea.

It is advisable to know at least something about rhododendrons before settling them at home. Because of the complexity of care, Azalea is called a capricious beauty. But if she settles in comfortable conditions, she will delight the owners with a healthy look and lush bloom. You just need to line up behind it so that everything is in balance.

Azalea feels great at an air temperature not higher than +22 ° C in summer and +15 ° C in winter. It should be bright enough, but without direct sunlight. It should be humid in a pot and air (80%), but it is impossible to spray during flowering. The soil needs to be acidic. Trouble begins when these conditions are violated.

If the leaves began to dry out, change color, become stained, you need to find out why this is happening and eliminate the cause. Leaves can fall off very quickly. They turn yellow as a result of the attack of pests - then you need to take action quickly. And if a lot of calcium has accumulated in the soil, then adding a little citric acid to the water will help.

The main cause of leaf fall is excessive dryness and high air temperature. As soon as the drying of the greens began, you need to lower the air temperature (this way the plant will recover more easily), pour settled acidified water, spray the flower.

If the azalea dries, it is necessary to give her a cool shower. Most likely, tap water contains a lot of salts and unnecessary impurities (which is why it is defended), so you will have to use a watering can with a fine sieve to bathe it with clean, settled water with the addition of citric acid. You can immerse the pot in a bowl so that the water is 2 cm above the edge, leave it for 20-30 minutes, then let the excess water drain. Just fill the flower with acidified water!

If the azalea is dry

What to do in the event that the azalea has dried up, completely losing its leaves? Do not rush to throw it away, even if it is dry. If the roots are still alive, i.e., not dried out, then the plant can be reanimated with water, cooling and boric acid. Just need to be patient.

First you need to get rid of the old soil. To do this, the plant is taken out of the pot, the roots and a clod of earth are poured. clean water. As the soil soaks, slowly and carefully remove (wash) it with your hands, you can substitute the soaked roots under running water and rinse. Then the plant can be planted in a new soil, purchased specifically for azaleas and laid on a high-quality drainage layer in a new pot. It is desirable to add to the soil wood ash or activated charcoal, put a layer of pine needles on top. The transplanted flower should be placed in a softly lit place with an air temperature of no higher than +20 ° C and left until the morning.

The next day, the plant must be watered with water that has been settled for at least two days, adding a few drops of boric acid and Zircon to it. When all the soil flows well with water, the excess must be poured out of the pan.

Roots will absorb better useful material at a low temperature, so the pot can be overlaid with ice. Some flower growers argue that in the summer, a pot of azalea should be put in the refrigerator for a day. Such procedures - watering with boric acid and Zircon, cooling - must be repeated daily until new leaves begin to grow. Then you can water every other day, sometimes replacing boric acid with citric acid, and replace the refrigerator with sprays.

How to reanimate after pests

Having got rid of the reason why the azalea, damaged by pests, dried up, you can start restoring the plant.

Affected leaves must be removed (if they have not fallen off on their own), bare branches should not be cut. In order for the azalea to revive its branches, it must be in comfortable conditions, but it is advisable to increase the humidity of the air even more by covering the plant with a transparent lid (bag, jar). To enhance immunity, it is sprayed with a solution prepared from the Elina preparation. Water frequently (daily or every other day) with acidified settled water.

How to reanimate after illness

Azalea diseases are the result of errors. These can be caused by fluctuations in air temperature, humidity levels. If the leaves of the azalea turn black, then the cause may be a black trias or infection with fungal diseases. Septoria (red-yellow spots with black dots), cercosporosis ( brown spots with red edges on the underside of the leaf), phyllostictosis (brown or gray spots) are characterized by the presence of spots that appear and grow on the leaves, stems of the plant. Late blight affects the roots, and the twisting and drying of the leaves indicates it, which first darken, starting from the very tips, change color, and then curl and.

These diseases will not be allowed to progress with special preparations that need to be started as early as possible: Bordeaux liquid, Fundazol, Ditan, Topsin-M or other fungicides. With verticillium, the base of the stem darkens, and not the leaf, this can most likely lead to death. Timely treatment with copper sulfate or fungicides will save. The sooner the disease is established, the sooner treatment will begin, which means there will be more hope for a full recovery of the plant.

After using special preparations, all affected parts of the plant must be destroyed in order to prevent the disease from returning. An azalea that has survived a disease needs restorative procedures no less than after an invasion of pests or drying out due to poor care. The main goals are the same: restore immunity, improve conditions, help absorb nutrients.

Azalea will certainly be transplanted into a new soil, be sure to check the condition of the roots. Then apply frequent watering and spraying with water with boric and citric acid alternately, sometimes using the Elina solution to enhance immunity.

It is important that at this time the air temperature does not rise above + 20–22 degrees, and the lighting is soft without direct sunlight.

Video "Why does the azalea wither"

From this video you will learn how to cure an azalea that has begun to wither.