Cacti: diseases and their treatment. Diseases and treatment of cacti - drying and rotting Rooting cactus cuttings
Use a suitable soil mixture. For most desert cacti, a mixture of two parts garden soil, two parts coarse sand and one part peat is suitable. This mixture allows water to pass through well and does not harden when dried.
Water the cactus only when the soil is dry. To check the soil moisture, press down 2-3 centimeters with your finger. If the soil is completely dry, water the cactus deeply and allow excess water to drain through the hole in the bottom of the pot.
When watering, consider the time of year. Cacti require different amounts of moisture during periods of growth and dormancy. From March to September, when the growing season lasts, water them on average once a month. During the dormant period, from October to February, cacti should be watered less frequently, no more than once a month.
Provide the plant with enough light. Most cacti require plenty of sunlight. In summer, keep the cactus outside and make sure it doesn't get rained on. To prevent sunburn, start by placing the cactus in a fairly shaded area, and then gradually move it to a brighter area. In winter, keep the cactus near a south or west window so that it receives enough light.
Monitor the room temperature. In winter, during the dormant period, cacti prefer lower temperatures. However, be careful to keep cacti away from drafts - do not place them near loose windows or on the floor near doors. In winter, the optimal night temperature is 7–16 °C, so during this period it is better to keep cacti in cool semi-basements.
As it grows, transplant the cactus into larger pots. As soon as the cactus grows so much that there is a danger of the pot overturning, or 2-3 centimeters remain from the plant to the edge of the pot, it should be replanted. Use a standard soil mixture: two parts garden soil, two parts coarse sand and one part peat.
- When replanting, make sure that the soil level is the same as in the old pot.
Trim away dead roots. With overwatering, when the roots are left in moist, poorly drained soil for a long time, they often begin to rot. When replanting, remove the cactus along with the roots from the old pot and carefully clean them from the soil. Inspect the root system and trim off soft, blackened, and dried roots. Prune close to where the living root begins.
Do not replant a cactus with damaged roots immediately. If, after removing the cactus from the old pot, the root system is damaged, or you have to cut off dead roots, keep the cactus out of the soil for about ten days. During this time, sagging forms in damaged areas and in places of cuts. Simply place the plant on a piece of paper so that it is not exposed to direct sunlight or low temperatures.
It is generally accepted that cacti are the easiest plants to care for. As if even an inexperienced gardener could grow a prickly pet without any problems. After all, with all his appearance he shows: “I am a strong and healthy plant, diseases are not mine, I will overcome pests.” Having believed this green “optimistic hedgehog”, many, without hesitation for a long time, purchase the plant. And after some time they encounter problems. It turns out that their prickly pet can also be sick. At first they don’t pay attention to the diseases: the cactus is so harsh and strong. And only when the patient is more dead than alive, treatment begins. Alas, it is often too late. How to prevent the development of cactus diseases, what to pay attention to when caring for this plant, and how to help if it becomes unwell? First, create conditions for comfortable living. Secondly, do not disturb the watering schedule. Third, watch your pet carefully. And when the first suspicious symptoms appear, immediately take measures to save the plant.
Experienced indoor plant lovers know that the cactus, despite its harsh appearance and spines, is quite delicate and vulnerable. To avoid health problems, it is first necessary to create favorable conditions. The best microclimate will be as close as possible to the one to which the plant is accustomed in its historical homeland.
If we are talking about cacti, we must immediately make a reservation: they are divided into desert and forest. Outwardly, with rare exceptions, they are completely different from each other; in nature they have adapted to live in different conditions. And at home, desert dwellers and tropical dwellers need different microclimates.
Desert People
You can easily recognize them by their fleshy stems, which can be of different sizes and the most bizarre shapes: resembling a ball, column, column, pancake, caterpillar. Most desert cacti do not have leaves; during the process of evolution, they atrophied, turning into spines.
This helped reduce the evaporation area. The only exception, which only confirms the rule, is the pereskia that has grown leaves and dispenses with the thick stem. All desert cacti have spines, hard or soft (like hairs), long or short, sparse or dense. Desert cacti amaze with their diversity, but you can easily recognize them as close “relatives” All people from the desert love the same conditions.
The most important thing is a lot of light, especially in winter. They have nothing against direct sunlight, although in the summer heat this is a bit difficult for the cactus; it is better to shade the plant. The soil needs to be light, loose, and moisture-permeable. Humidity will be moderate or low (40–50%). The air temperature in winter should be cool, 15–18 o C. Most varieties (except pubescent ones) will tolerate “frosts” of about 5 o C without harm. In winter, cacti hibernate.
This is another prerequisite for maintaining health and harmonious development. During the rest period, your “hedgehogs” do not want to drink at all; watering is needed rare and meager. With the beginning of spring it is gradually increased, bringing it back to normal by summer. By mid-autumn, watering is again limited.
Give warm and soft water.
Aporocactus, which belongs to the forest category, has desert habits. But the rest require special conditions for a healthy life. They like light that is bright but diffused. They will like the substrate to be airy and light, slightly acidic. The temperature is moderate (22–25 o C), during the rest period it is cool (15–17 o C).
Each species has its own hibernation time. Zygocactus rests from January to March. Ripsalidopsis - in September-February, the epiphyllum “takes a vacation” for the whole winter. Since the plants are quite similar, this is a good criterion for identifying them.
The irrigation regime depends on the life cycle; only soft, lukewarm water is used. During hibernation it is sparse and scarce, but during bud formation, flowering and active growth it is abundant. But all forest cacti, regardless of the time of year, prefer tropical high humidity (70% or more).
A typical representative of forest cacti is epiphyllum; it is quite difficult to suspect even a distant relationship with desert cacti
The most important condition for the health of a cactus is compliance with the conditions of detention. Even a slight deviation can lead to illness. They poured cold water on it, opened the window where the plant stood in the frost, and a week later some spots appeared on it. If you ignore these symptoms, you may lose the cactus altogether. With them, as with other living beings, disease is easier to prevent than to cure.
Mandatory prevention
Some cactus diseases cannot be treated. But they can be prevented. Prevention for your pet's health is not only compliance with living conditions, but also hygiene. There is no need to wash your hands before watering the plant. It is highly desirable to ensure phytosanitary control at the entrance to the apartment. What does it mean?
Before making a purchase, carefully inspect the cactus; If there is the slightest damage or suspicious marks on the skin, refuse to purchase
Even if, in your opinion, the plant is absolutely healthy, do not flatter yourself. Problems may appear later. Don't put the newbie next to the rest of the cacti. Keep him in isolation for at least a month. Only after quarantine “introduce” him to the rest of the neighbors on the windowsill.
Before planting, the soil must be sterilized by exposing it to cold, steam or heat.
Desert and forest cacti may suffer from the same diseases, but there are also differences. For example, epiphytic plants have a poorly developed root system, so they are not affected by root nematodes and root insects. Desert cacti are not often harmed by slugs; they have difficulty breaking through the thorns and thick skin.
Table: mealybugs, aphids and other diseases and pests that affect plants
Make a diagnosis and save the plant
If the appearance of the cactus has not changed for the better, development has stopped, analyze the possible reasons. And then you can determine what happened. These could be errors in care or illness. External symptoms will help make a diagnosis and prescribe treatment for a prickly patient. Sometimes help comes too late. Then an autopsy will show what the cause of the disease is. And you will be able to save other plants living in the house. So, what does a cactus look like when it is unwell and what happens to it?
Table: why the roots turn black and rot, the stem withers, the plant dries out, spots appear, white coating, mold and other problems
Pay attention to cactus injuries. Mechanical damage (cracks, wounds, cuts) is not scary in itself. This is a gateway for infection. If the wound is not treated, the cactus can become infected and become seriously ill. Be sure to disinfect the damaged area by sprinkling it with activated carbon, crushed chalk or colloidal sulfur powder, and dry it.
During the healing process, the area will become covered with a layer of dead cells and then heal. If you don’t have anything on hand, regular iodine or brilliant green will do.
Diseases of cacti caused by fungi and bacteria: how to recognize and how to deal with them The fleshy “body” of the cactus is a kind of storage room for storing nutrients and moisture.
In such an environment, pathogenic fungi, bacteria and viruses actively multiply. Sometimes an inexperienced cactus grower himself helps his plant become a “canteen” for harmful microorganisms. Overmoistening of the soil and air, especially in winter, non-compliance with temperature conditions, contaminated soil are factors that help different types of rot spread. And these are the most dangerous diseases of cacti.
Table: fungal and bacterial diseases of cacti and their treatment
Brown rot can be treated only in the early stages of the disease. The most dangerous helminthosporosis is for young cacti and seedlings grown from seeds. The most common cause of rust is drops of cold hard water that fall on the cactus during watering. Gray rot is one of the most common fungal diseases that affects cacti It is quite difficult to notice dry rot that has begun to develop in a timely manner. The fungus that causes late blight most often penetrates the cactus tissue through “wounds” caused by mechanical damage to the skin. The development of fusarium is often provoked by the grower himself, by abundantly watering cacti that do not need it
When rot has affected the root system, there are two methods of control:
Application of some fungicides
Fungicides are the most effective remedy against fungal diseases
Diseases caused by metabolic and nutritional disorders
What other diseases do cacti have? These are non-communicable diseases that are caused by care errors. The most common are chlorosis, etiolation, deficiency or excess of macro- and microelements.
Chlorosis is a disruption of the process of photosynthesis. The stems of the cactus become discolored, turn yellow, and white spots appear on them. Treat the plant with Fitoverm several times at intervals of 3–4 days. Feed the cactus. For prevention, spray with iron chelate (Antichlorosin). Some gardeners advise burying a rusty nail in the ground to provide this microelement to the soil.
A cactus affected by chlorosis turns completely or partially yellow
Etiolation is a disease of light deficiency. If a cactus does not have enough of it, it stretches out unsightly and becomes discolored. Place the plant on the sunny side, add artificial lighting in winter.
Pests
Insects also love to feast on fleshy, juicy cacti. The main pests of cacti are nematodes, aphids, spider mites, mealybugs, and scale insects. During summer holidays in the garden, cacti may be attacked by slugs and snails.
Aphids on cacti are a common occurrence, despite the tough skin.
And yet, most cacti are distinguished by excellent health. Problems and infections arise when the owner of a green hedgehog neglects the rules of caring for the plant. And then for quite a long time he does not notice the SOS signals sent by his pet. If you create acceptable conditions for the cactus, follow the watering schedule, and give it a rest in the winter, your “thorn” will not only live long and happily, but will also delight you with wonderful flowers. And this is one of the best rewards for a cactus grower.
Overfeeding with fertilizers - the stem cracked.
The causative agents of cacti diseases are bacteria, fungi and viruses. Some diseases can be cured quite easily, but most cause significant damage to health and lead to the death of plants. Sometimes the symptoms are so imprecise and occur in a latent form that it is not possible to determine the disease.
Therefore, it is much easier to prevent diseases than to cure the sick, especially when there is not just one cactus, but a whole collection. Preventive measures include strict adherence to plant maintenance conditions and hygiene.
Unfortunately, in most cases, cacti diseases end sadly. The plant either dies or is disfigured. And still, most cactus growers are tormented by two questions: “why?” and “how to treat.”
Even after all the repeated explanations that in most cases the cause of disease is a violation of the conditions of detention, people cannot believe that just from opening a window once (in the evening in cold weather) an unfortunate cactus can become covered with rusty spots and the like. But in reality it is so. Even an experienced cactus grower suffers losses from his fleeting mistakes. Only compliance with all conditions, attention and prevention can prevent the occurrence of diseases.
The fact that a cactus is “sick” is not always immediately obvious. What is most often forgotten is that:
- opened the window in the evening in cool, windy weather;
- poured cold water over the cactus;
- that any wounds, cracks and cuts should be sprinkled with sulfur or crushed coal;
- A cactus must be gradually accustomed to the bright sun, even the most sun-loving one;
- that cacti need a cool and dry winter.
If a cactus gets sick, first of all you need to remember and analyze what violations might have occurred in the conditions of detention, and whether you did everything correctly.
Sometimes disease, pest damage or the result of care errors is not immediately visible. How to understand that something is “unhealthy” for a cactus, something is bothering it - just be careful. You should worry about the cactus in the following cases:
| External signs | Possible reasons |
|---|---|
| If there is no visible growth of the cactus (only in spring and summer) | Lack of plant growth in spring or summer is the first sign of some kind of trouble. The reason for this can be absolutely any: disease or pests, or an error in care - first of all, lack of light, moving the cactus to a new place, improper replanting, watering with cold water, etc. After vaccination, as it causes a stressful situation. After too long and intense flowering, growth may also slow down or stop due to exhaustion of the cactus. |
| If the stem shrinks or shrinks | If the stem is hard to the touch, then first of all you should exclude a lack of moisture in the soil (i.e. watering, the soil is dry), especially if the cactus is in intense light. If the stem, on the contrary, is soft, then the reason is most likely in excess moisture (the soil is damp); at this stage the plant can rarely be saved; you can try an urgent replanting with the removal of all rotten roots. |
| If there is a change in color of the stem or leaves | This is a fairly common reaction to changing conditions. When moving a cactus to a new location. When the light changes (if the light is too bright, the stem and leaves may become light or red). When water gets on the stem or leaves (if the plant does not tolerate this). Some cacti are genetically programmed to change color with age. With some diseases, the color of the stem and leaves may also change, most often yellowing, browning and mosaic coloring appears. |
| If leaves or buds are dropped | This may be the first reaction to a stressful situation caused by changes in living conditions. Rearrangement to a new place or even because the cactus was turned the other side towards the light source. If lighting, watering or temperature suddenly changes. For example, they poured cold water on it. If the transplant is carried out at the wrong time or incorrectly. From the discrepancy between micro- and macroelements in the soil. This can also happen due to disease or pest damage. |
| If shoots die off | This happens most often when the roots are damaged during replanting or watering with cold water. From a sharp drop in temperature or exposure to a draft. This can also happen due to disease or pest damage. |
| If various spots or yellowing appear on the skin | This is possible from water getting on the stem or leaves (if the plant does not tolerate this). An untrained cactus can get sunburn from exposure to sunlight. Exposure to cold air may cause rust spots to form on the stem. If there is a lack of nutrients in the soil, yellowing may occur, which disappears after fertilizing with mineral fertilizer. Yellowing or spots also appear due to various diseases and pest infestations. |
| If wounds or cracks appear on the cactus | This howling can be caused by mechanical injuries. When there is an excess of organic matter in the soil, the cactus grows vigorously, and the skin cracks and bursts. |
| If damage or rotting of roots is detected | The cause of root rot should be sought primarily in waterlogging of the soil. Especially with a lack of light and low temperatures. Root rot often begins when damage, cuts or wounds on the roots are not treated with sulfur (which is needed for drying and disinfection). Insufficient soil moisture at high temperatures and light levels can lead not to rotting, but to the death of some of the roots. This happens especially often when the pot overheats in the sun in summer. |
| No flowering or short flowering. | A common reason is a lack of sunlight, lack of a cold winter (rest period), any violation of watering regimes and temperature. Some cacti, on the contrary, do not bloom due to too intense or prolonged lighting. Incorrect or untimely transplantation. Inconsistency in soil pH or composition. Lack of nutrients in the soil or their excess. Rearranging the cactus to a new place or turning it in place. Diseases and pest damage are also the reason for the lack of flowering. |
Cactus rot
Rot is the most common disease, most often caused by improper care (excessive watering, cold wet wintering, etc.). Rot is caused by both fungi and bacteria.
Cactus late blight(the causative agent is the fungus Phytophtora cactorum), for example, affects all parts of the plant, especially if there are damage or wounds, but the root collar is most susceptible to the disease. Rot appears, as we imagine it in the form of decay and transformation of tissues into a soggy mass.
Among the rot it should be noted Helminthosporiosis(pathogen is a fungus of the genus Pyrenophora) - a disease of crops - the stems of cacti become bent and dry out, and literally in a few days. Another crop disease is Rhizoctonia (caused by a fungus of the genus Rhizoctonia) or wet rot, which manifests itself in darkening, blackening of the cactus stem, spreading upward through the vessels. Both diseases can be avoided if you disinfect the soil for sowing, treat the seeds, and also avoid high humidity in the greenhouse.
It should also be mentioned fusarium(the causative agent is a fungus of the genus Fusarium), which is detected suddenly - the cactus falls, the color of the cactus stem changes (becomes reddish, brown or purple). If you take the plant out of the pot, its roots are torn off and may be completely rotten, depending on the stage. The cactus is poisoned by toxins released by fungi into the plant’s vascular system, which is noticeable on the cut of the stem - a darkened, clearly visible brownish ring.
Treatment of a rotten cactus
If rot affects the root system, then there are two options. The first - if the rotting of the roots is only partial (in the very initial stage, usually discovered by chance) - all affected parts of the roots are removed, and the rest are well sprinkled with coal powder or sulfur and the cactus is planted in fresh soil with a large proportion of sand. Watering only after three weeks is very careful. The second case is when the roots have rotted completely - you can still save the upper part of the stem by rooting it like a cutting. In this case, part of the stem is cut off so that only healthy, strong tissue remains. If the root collar or stem has begun to rot, then only the top of the cactus can be saved by grafting it onto another healthy cactus.
It happens that stem rot begins at the site of the wound on the skin of the cactus. If the rotting area is not yet large, then you can cut out the rotted tissue with a sharp knife, and carefully sprinkle the area with sulfur. If the wound is small, a scar will remain and the plant will recover. But if the damage is significant, the cactus will be disfigured.
If decay has occurred at the very top of the cactus, then it must be cut down to healthy tissue, and the cactus must be used as a rootstock for grafting. You can disinfect all wounds on the body of a cactus with charcoal (you can crush an activated carbon tablet), sulfur, and also brilliant green.
If you cut the top of a cactus for rooting from a diseased plant, then prepare a disinfected substrate, which must be absolutely dry. Dry the cactus cutting in the air for a couple of hours, sprinkle the cut with charcoal powder, then place it on the substrate, do not dig in! Do not secure the low crown of the spherical cactus - it will not fall, and if the cutting is unstable, secure it on several sides with large pebbles. There is no need to cover the entire substrate with gravel on top; a couple of stones are enough.
It can be secured in another way. Stick a stick firmly into the ground and tie the cutting to it with a woolen thread. After this, do not water the cactus for at least 2 weeks. If it's a hot summer, i.e. high air temperature, then instead of watering the cactus trunk is sprayed with a very fine spray bottle, or they pollinate and humidify only the air around the cutting. After 2 weeks, you can slightly moisten the soil in the pot not by watering, but by spraying, so that it remains wet for 2-3 hours, then dries. You can always lift an unrooted cutting and see if new roots have appeared. If they appear, then the cactus should be left alone (not raised again), and the spraying of the soil should be gradually increased.
If you are saving a cactus that has rotted in winter and is in a dormant period by re-rooting a cutting, then you will be forced to place it in growing conditions - the roots will grow only in warmth and with sufficient lighting. Therefore, if you place a cactus in a warm room, evaluate whether it has enough light; if necessary, place a fluorescent lamp nearby. In some apartments, placement even on a southern window sill is not enough to provide adequate lighting in winter.
Black rot (caused by the fungus Alternaria radicina) - when black (dark brown spots) appear on the trunk of the cactus, in the form of streaks, wet, shiny and disgustingly scary. The disease can spread very quickly. It is necessary to cut out all stains to healthy tissue. Spray the plant with foundationazole, Oksikhom or Khom, and dry the cut areas with sulfur.
Dry rot (caused by the fungus Phoma rostrupii) or Phomasis - in the direct sense, rotting is not observed, this is simply what this disease is called. It is dangerous because when it is discovered, it is usually too late. Outwardly, the cactus turns slightly pale and begins to dry out imperceptibly. If you cut the stem, the cactus will be dry inside. Since this disease is transient and no methods have yet been invented to combat it, the plant dies. However, the disease can be prevented by periodically preventative spraying or watering with a systemic fungicide.
Spots - their nature is very diverse, most of them are caused by viruses and bacteria, the appearance of which was facilitated by the conditions of detention. This is primarily the effect of a cold draft, especially in winter, or damage to the cactus in conditions of high humidity and cool air. One of the varieties of spotting rust- the stem becomes covered with rusty crusts or streaks. The cause of the disease can be sunburn, water (especially cold) getting on the stem and a sharp drop in ambient temperature, etc. The bad thing is that once these rust spots appear, they begin to appear in other places and spread more and more. Sometimes spraying with a fungicide inhibits further spread of the disease, and sometimes not; Topaz is used as an anti-rust agent. It is completely useless to try to remove the crusts or spots; ugly scars remain in these places.
Very often you can notice that if you buy, for example, a diseased cactus with unidentified spots and place it at home in a well-lit, sunny place in a warm place, the spots do not increase and new ones do not appear. This happens often, especially when affected by fungal diseases. Any mushrooms do not like the combination of heat (dry air) and light. Once on a sunny windowsill with moderate watering, the cactus recovers on its own.
But if, in a warm sunny place, reddish or whitish spots, sometimes similar to mica, appear and spread along the stem of a cactus, then the problem is a mite, which just likes such conditions...
Brown spot, or anthrocnose(caused by a fungus of the genus Gloeosporium) - in cacti it manifests itself completely differently from other plants. On the stem of the cactus, spots from light to dark brown appear anywhere, both on the sides and on the top. The spots are dry, depressed, forming a dry crust. The spots slowly increase, covering increasingly larger areas. Fight in the same way - cutting out the affected areas and treating with fungicides.
Brown rot (caused by the bacterium Erwinia) - darkening of the cactus stem occurs, usually from the root collar or from any other place (for example, if there was mechanical damage to the skin of the cactus and the pathogen entered it). At the same time, the cactus itself becomes soft to the touch, and gradually changes color to dirty brown. After some time, when the cactus is broken, you can see a slimy jelly-like mass. As a rule, it is not possible to save a cactus - bacteria and their toxins quickly poison the entire plant.
Yellowing - the cause can be either a lack of nutrients in the soil or a bacterial or viral disease. Yellowing usually begins at the ends of the shoots and the top of the cactus. First of all, you should eliminate the lack of nutrients and feed the cactus with mineral fertilizer - if this is the reason, the yellowing will go away. General yellowing can also be caused by a virus, the so-called “jaundice”; there is no way to fight the disease. It can pass quickly, or it can last for many months and even years. Moreover, if you take an absolutely healthy-looking cutting from an infected plant, then after a while it will turn yellow.
Viruses in cacti
Viruses are found on cacti much less frequently than expected. In fact, like other plants, viruses have characteristic features that allow them to be identified, except in cases where the body of the cactus is densely covered with spines and it is impossible to clearly see the pattern. And the pattern in viral diseases can always be traced.
As a rule, these are concentric rings, various spots that have a certain sequence of appearance on the stem, for example, the entire trunk of a cactus seems to be speckled - it looks very much like it was sprayed with acid. Some people think that this is sunburn after spraying, but it turns out that the plant was not sprayed or it was not standing in the sun. The spots are usually light - in this place there is no chlorophyll in the cells. And only cacti infected with the virus that are artificially maintained in culture have a solid, beautiful stem color - red, yellow, white, etc. is a genetically fixed disease.
By the way, it is grafted cacti that are most often affected by viral diseases.
If you suspect that the cactus has become infected with a virus, you can try using antiviral drugs sold in pharmacies for people, for example, rimantadine (1 tablet per half liter of water).
An incident from the life of the forum: “When I saw the Gymnocalycium, I bought it right away (although I swore off buying Dutch ones). Now I don’t know whether to plant or throw away, because, in my opinion, there is nothing to re-root there, since they are relatively small. They are at the bottom The roots were all kind of wrinkled and some had some sores on them. There were five of them in one pot of different colors. " Maybe there's nothing wrong..."
In fact, these cacti did not grow, although the roots, as can be seen in the photo, are healthy. So, in addition to the fact that the lower part of the stem of a buried cactus can quite naturally lose color (the process of photosynthesis does not occur and it becomes yellowish-brown), in addition to the fact that for many species it is natural for the lower part to become suberized due to contact with water and soil and lack of light, this cactus has a fungal infection, as evidenced by an unevenly spreading yellowing spot, as well as brown crusty spots.
The fact that the roots are healthy gives hope that the plant can be cured, wait for new growth, and then re-root the top to get rid of the deformity. For treatment, you can use Hom, Oxychom, Fundazol or Quinozol. Dilute the fungicide according to the instructions and bathe the cactus in the solution. Then take a new soil mixture, sterilize it (for example, keep it in a very hot oven for about 30 minutes, after which it should be completely dry, cool).
Then plant the cactus and place it under diffused light. After 3-4 days, depending on the air temperature, water with a fungicide solution. Repeat treatments on the stem after a week. If the cactus was in a dormant period, it will have to be awakened - moved to a warmer and brighter place, and drip watering started. In general, cacti are brought out of hibernation by starting regular spraying with a fine sprayer. But if the cactus has a fungal or bacterial infection, spraying can make the problem worse. Therefore, it is better to start watering little by little. Feeding with fertilizers, spraying with zircon or epin is also not necessary! Stimulants will not help, but there will be enough nutrients in fresh soil. If there is enough light (additional artificial lighting can be installed), the treatments are carried out, such a cactus has a significant chance of recovery.
How and how to treat cacti
All rot, spotting, fungal or bacterial origin is aggravated in conditions of high humidity. Those. At the time of illness, any spraying (with the exception of fungicide solutions), wet weather outside, etc. is dangerous. If, for example, you are fighting flat mites or spider mites on a cactus by spraying (with or without insecticides), reduce watering! Temperature is of secondary importance, but the most severe damage occurs if the plant was kept in cool conditions and high humidity.
It is very difficult to determine whether a fungal or bacterial disease has affected a cactus; most often, a fungal infection occurs. Bacterial rot is characterized by the formation of soggy mucus, often with an unpleasant odor (but this is already at the last stage, when almost everything in the plant is affected) and the transience of the disease. Bacteriosis can literally destroy a plant within a day.
Fungal diseases spread at different speeds and depending on the conditions; if the cacti are on the balcony and the weather is rainy at that time, the disease progresses. But even if spots and other types of lesions (darkening at the root collar) do not increase and do not spread further, it is advisable to treat the cactus with a fungicide.
Fungicides work against fungi and bacteria; they are powerless against viruses. Again, there are specifics. For example, the systemic fungicide "Maxim" is effective against root rot and rotting of the root collar.
Some use a drug such as Fitosporin to combat and prevent rot; it should be noted that it is very unreliable when the plant is already sick. You may not observe any improvement; you should only rely on stronger drugs.
When spots and rot appear on the cactus trunk, on the side or on the crown, spraying with preparations such as Hom, Oxychom, Bordeaux mixture, foundationol, topaz is effective. Colloidal sulfur helps against some fungal diseases, such as brown spot. It is not diluted in water as written in the instructions for use, but the stains are dusted with a paint brush.
Fungicides for the treatment of cacti
Among the chemicals used to treat cactus diseases are: Kaptan- an organic fungicide, a substitute for Bordeaux mixture, used in the form of a solution (0.3 - 1%) for watering and brushing, or in the form of a powder by dusting (insoluble in water). This drug is effective against many fungal and bacterial diseases, but does not work against powdery mildew. It cannot be used with lime (as it hydrolyzes in the presence of alkalis).
It is also used to combat pathogens of various diseases. It is used in the form of a solution (0.005 - 0.1%). It is sprayed or rubbed with a brush on the stems and roots. The working fluid is not stored.
Sulfur- to combat fungal diseases and mites. Sulfur is an insectofungicide. It is used in the form of an aqueous solution, but sulfur does not dissolve in water, it is only wetted. Therefore, it is more effective to dust plants with a gray brush.
Quinozol- a preparation for protecting plants from diseases caused by phytopathogenic fungi (contact fungicide-protectant). Available in powder form. Quinozol is used against fungal as well as bacterial rot. If you don't find this drug in a gardening store, you can find it in a pharmacy. For humans, quinosole is marketed as an antimicrobial agent. You need to crush the tablet into powder and thoroughly dissolve it in 1/2 cup of water. Moisten the cactus trunk with this solution and pour the soil under the root. Can also be used to disinfect soil and treat seeds. The working fluid is not stored.
Maksim- a preparation for protecting plants from diseases, a disinfectant. Used for seed treatment and soil disinfection (from fusarium, fomoz, wet rot, etc.). The difficulty may be that root rot appears from waterlogging and excess watering, even with Maxim's solution, is impossible - you need to let the soil dry thoroughly. Dilute 4 ml of the drug into 50-100 ml, pour the soil with this solution, soak the seeds, and moisten the trunk and leaves of the cactus with a brush or spray. The effect of the drug is about 10 weeks after treatment. The working fluid is not stored.
Topaz - the drug is used to protect against powdery mildew and rust. 1 ampoule is diluted in 5 liters of water. The duration of action is about 2 weeks. At least 3 treatments are required.
Hom(copper oxychloride) - a means of combating diseases (Late blight, macrosporiosis, brown spot, anthracnose, rust, various bacterioses and spots). One of the most effective drugs against diseases of cacti, succulents and other plants. Dilute 20 g of powder per 5 liters of water. Spraying is repeated as necessary up to 5-6 times. The duration of action of the drug is about 2 weeks. The working solution is not stored.
Fitosporin- biofungicide to protect plants from fungal and bacterial diseases. In fact, this drug is effective only in the initial stage of the disease. The opinion of many gardeners: it should be used only when there is no other fungicide at hand and for treating the soil after sterilization by heat treatment - i.e. as prevention. To prepare the solution, dilute the paste on the tip of a knife with 1 teaspoon of water. Then take 4-5 drops per glass of water and water the ground or spray the plant.
Treating seeds and disinfecting the soil before planting cacti (seeds and adult plants) saves seedlings from diseases. If it is enough to thoroughly steam the soil against pests, warm it in a microwave, oven, or steam, then this is not always effective against fungi and bacteria, and freezing is completely useless.
Therefore, before sowing seeds or transplanting cacti, it is advisable to spill the steamed soil with a solution of a fungicide, for example, foundationazole or quinozol. After this, of course, let it dry.
Emergency surgery.How to save a rotten cactus?
External signs of cactus diseases, which should alert you and prompt you to study the specimen in more detail.
The cactus “turned pale”, the epidermis began to turn yellow and stopped shining.
The cactus has shrunk a lot, especially if this happens during the growing season with normal watering.
The cactus looked sideways.
Spots appeared on the cactus (wet, dry, depressed, suberized, differing in color from the color of the epidermis of the cactus.)
A sort of “dent” appeared on the cactus, on one side, usually closer to the top of the stem.
Stunting and dropping during the season with normal care and the condition that this species should be growing at this time! (Let me explain, there are species for which it is completely normal to go into a dormant state in the middle of the season when the weather is especially hot. These include ailostera, rebutia, etc.)
Also, an indirect sign of death or rotting cactus roots May be soil in a pot that does not dry out for a long time. This is especially noticeable when you have several cacti watered at the same time. For example, after a week, the soil under all the cacti is already dry, but in one pot the soil remains wet, as if it had just been watered. This suggests that the cactus for some reason “does not drink” water. Upon examination, it often turns out that such a cactus problems with roots.
Treatment of a sick cactus
Rotting cactus without external signs
The first thing to do is to exclude all watering and not even spray the sick cactus. Treatment of all cactus sores is based on removing the affected areas and then drying them. This is where a scalpel from cactus first aid kits . The next step is when« somethingit’s not the same with the cactus,” but there are no obvious signs yet - this is removing the patient from the pot and studying the roots, if any are found. If there are no more roots, then follow the instructions below and immediately proceed to pruning for .
V nNormally, cactus roots should be grayish-white and not crumble or break.Are your cactus roots healthy? Then you here. Rusty-yellow and raspberry-brown spots indicate the presence of a fungal infection on the roots of a cactus. To cure a sick cactus, proceed as follows.
With a clean and sharp scalpel or knife, all roots with signs of damage are cut off. We look at the sections, if the sections on the roots are not white, but with red dots or splashes (photo on the left), then
We cut further and so on until a healthy place. It happens that this process endsalmost at the top of the cactus........... If he stopsIf you do it for humane reasons and do not cut off the damaged parts, the process will resume and you will most likely lose the cactus. Therefore, even if you have removed all the roots up to the root collar, but spots or spots remain.....continue cutting yourself cactus. Cut it off
in thin, even circles (well, almost like cutting a cucumber for a salad) the first clean, green, undamaged cut will not appear (photo 1). Now we make a control cut with a clean, disinfected knife and remove the side areolas (the places from which the spines grow). That is, we essentially “sharpen” the rest of the cactus, like a pencil (photo 2). If this seemingly strange procedure 
not done, the place of the cut during drying and scarring will be drawn into the cactus as ifand it will be very difficult for it to take root (photo 3). It will be impossible to place such a cactus cutting on the ground; it will not reach the cambial ring (the central part of the cactus from which the “correct” roots grow) to the ground and will have to be planted on a “mound.”Moreover, the probability increases that in the “retracted” part of the cactus they will begin to develop
I are unwanted, harmful fungi that can cause even healthy cactus cuttings to rot.This is always very inconvenient and is suitable for those cases when, after trimming, essentially only the top of the cactus remains and there is simply nothing to “sharpen.” Such crowns are usually rarely able to take root on their own and require, but we'll talk about this another time.
External signs of rotting cactus.
Another example of cactus rotting. In this case, the signs of the disease are already visible, although not clearly expressed. With a cursory examination and a certain lack of experience, the lesion can easily be missed. In this case, a mixed infection (late blight + fusarium) on the lateral process of the mammillaria. The photographs below (photos 4,5,6) were taken from different angles so that you can better understand what the rotted area of the cactus looks like. What do we see when examining a cactus? A slight change in color, the green epidermis lost its shine, darkened and began to look brown. The distance between the papillae was greatly reduced, so that the spines almost stuck to each other, and the baby mammillaria seemed to shrink. For comparison, pay attention to the healthy cactus babies on the left and right in the photo, they look completely different.
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| photo 4 | photo 5 | photo 6 |
The process has become soft to the touch, the areolas with spines fall off at the slightest touch (photo 7). After removing the rotten shoot (photo 8), it is discovered that the lesions go deep into the body of the cactus (photo 9).
Intense pink color is the natural color of the base of the mammillaria. Yet red-yellow dots, spots and specks- these are areas affected by the fungus that need be sure to cut , even if it means cutting out half of the cactus. Otherwise, as was already written above, the rotting will continue.Do not forget to frequently wipe the scalpel or knife with a swab soaked in alcohol or vodka, since the instrument also transfers fungal spores to healthy parts of the cactus during subsequent cuts.
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| photo 7 | photo 8 | photo 9 |
Yellow “dots,” which are actually the affected part of the cactus’s vascular system, pose a particular danger. By removing all large areas of rotting, but leaving such a “point”, you will allow the fungus to reach the very top of the cactus and kill it. If the cut is already clean, but there are a couple of “dots” left, then in order not to cut too much, you can try to cut out only them directly (like eyes on a potato).
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| photo 10 | photo 11 |
After the surgical intervention, the cactus received a significant hole in the side, which must be sprinkled with crushed coal (photo 10,11). In the case of this cactus, inspection of the roots was not required, but if, during cutting, it turned out that the rot had spread to the root collar (you will immediately notice this, the lesions will be below ground level), then removal from the pot and inspection of the roots is necessary. Now the sick mammillaria needs complete dryness, warmth and time for the damage to heal. High air humidity is unacceptable.
The medical history of this mammillaria ended well. Huge hole in the side 
successfully healed and over the past few years has acquired a fair number of children who completely closed the defect. The cactus is alive, healthy and continues to delight me with flowering.
In addition. Please note, even if you did everything correctly, this does not mean 100% that the cactus will survive. Therefore, if your patient has children (shoots), then it makes sense to play it safe and separate one of them from the mother plant (preferably away from the place of rotting), for subsequent rooting, so as not to lose this type of cactus in the collection.
Rooting cactus cuttings
And the last phase of the rescue operation. Sprinkle the cut, crushedcoal fired,
which is an excellent disinfectant.In principle, even without coal, a cactus can heal perfectly; moreover, I do not always perform this procedure, so as not to impair the possibility of inspecting a cut of a cactus for secondary decay. In some cases, sprinkling with charcoal is vital, for example, for cuttings whose cut surface turns out to be excessively wet, when the cactus simply oozes juice. In this case, the coal additionally absorbs excess moisture, preventing the development of pathogenic fungi on the cut surface, which, under conditions of high humidity,
indoors, they can attack even a completely healthy cutting taken for rooting to replenish the collection of cacti.
Place a cactus, verticalflax into any suitable glass or something similar, so that the cut does not come into contact with the bottom and walls of the container (photos 1a and 2a) and leave it in a warm place. You can simply leave the cactus in an inverted position with the cut side up; it will “stand” perfectly on its own spines, but this method is suitable for small cactus cuttings. This is necessary in order to “wound
“I am part” of the cactus was constantly ventilated and dried. Now all that remains is to wait until the cactus has thoroughlythe cut part dries out and corky tissue is formedb (callus). This process can take from several days to two weeks or more; there is a direct relationship between size and time. The less is left of the cactus, the less viable it is and the sooner it will be necessary to try to root it again. And vice versa, the larger the cactus, the longer it will dry out to the required state and be able to remain without food,without much harm to yourself. 
The main thing is not to go too far. Hurry too much - the cactus may rot again; overexpose - it will not have enough strength to take root. The dried cactus cuttings are placed on light, loose, slightly moistened soil. They do! Do not bury or deepen, as this can cause rot. For stability, you can line it with pebbles. The pot with the cuttings is left in a warm, well-lit place, but without direct sunlight. Further care for the cactus consists of
periodically spraying with warm water.
Possible problems when rooting cactus cuttings.
Be patient and wait, rooting can take quite a while, from a couple of weeks to several months. Very tiny cuttings, the size of a pea, take root most quickly, although such cacti are babies and require more careful care. If necessary, I root such little ones in a mini greenhouse for seedlings, where the temperature is about 22 - 25 degrees, artificial lighting and the pot with the cutting is covered with a glass to prevent drying out. I usually place it slightly tilted on one side so that there is a gap for air circulation. This does not cancel ventilation! A couple of times a day, the cup should be removed for 20-30 minutes. Large cuttings of cacti from 5 - 7 cm or more for 2 - 3 months, and sometimes more, can be in thought: “Should I take root or not take root?”
The time of year also plays an important role when rooting cactus cuttings. The process is the hardestin autumn and winter when the cactus is in a state of stagnation.It is during these seasons that most often a defenseless, sleepy cactus is subjected to a vicious attack by fungi and bacteria, and as a result, it needs to be re-rooted within an hour. On a cold windowsill, with low lighting levels and short daylight hours, the chances of successful rooting of a cactus cutting are greatly reduced (especially for small cuttings) and spraying and moistening the soil in this case should be almost excluded. If possible, it is necessary to create more “spring-summer” conditions for the rooted cuttings. Lighting 12 - 14 hours a day at a temperature of about 20 - 22 degrees, will stimulate the cactus to awaken and attempt to release roots. But alas, this is not a panacea and works somewhere in 70 - 80%. Almost 100% survival rate of a rotten cactus or part of it can be achieved byto another cactus, most often Echinopsis. But even here there are some problems, firstly you need to master the grafting technique, and secondly......have an “extra” echinopsis on hand ( Echinopsis) suitable in size, which will be beheaded by you for the sake of saving a dying fellow.
I strongly recommend that you inspect the rooted cactus cuttings about once a week for secondary rotting or the appearance of mold; the same thing happens if you overdo it with spraying. Since cactus cuttings are simply placed on the ground for rooting (the exceptions are cereus and similar tall cacti with a small diameter, here a slight penetration into the ground is permissible), then it is enough to slightly move the cactus with tweezers to understand whether it has taken root or not. If it does not hold onto the ground, then lift it and inspect the cut surface. The cut is dry and clean - place the cactus back on the ground. If there are signs of rotting, re-process the cutting as described (cut, sprinkle with coal, dry) and set to root again, but now on "dry" rooting, that is, absolutely dry soil and no spraying of any kind until the waiting roots appear (see photo below). If there is mold (more often it happens on incorrectly sharpened cuttings, photo 3 on the page above, in the section ), then sprinkle the cut with charcoal, dry the cutting for a couple of hours, place it back on the ground and reduce the frequency of spraying.
On photos 
on the left, a correctly sharpened and dried cactus cutting, which has released adventitious roots from the cambial ring (in other words, embryonic or waiting roots), from which a full-fledged, healthy root system of the cactus will soon develop. These cactus roots are very fragile and must be handled with care.
Let's look at the main diseases of cacti and their treatment. Most often, cacti are affected by spider mites, various rots, viral infections, and the stem becomes covered with brown spots. The cactus rots due to waterlogging of the soil, in some cases it is a fungal infection, spotting is also a consequence of waterlogging of the soil in the pot, but it is also caused by viruses. Brown spots are the result of a burn or viral infection of the stem. Spider mites are the result of dry air and insufficient watering.
So, diseases of cacti and their treatment with photos and detailed explanations from specialists. What to do if the cactus is rotting, spotted or yellow?
Cactus diseases due to improper plant care
Why did the cactus begin to rot and turn yellow? In this case, it is necessary to pay attention to the conditions under which the plant is kept. So, a cactus rots if it is given the wrong wintering.
The first reason why a cactus begins to rot from below is improperly organized wintering.. In temperate latitudes, cacti have a cold winter. This is a temperature of +12...+15 degrees, a lot of light and a minimum of moisture. Why do cacti need a cold winter? The explanation is simple: in the conditions of an ordinary apartment, with the onset of winter, it is difficult to provide the plant with the necessary care. This is a high temperature, the length of daylight hours is above 14 hours. With a lack of sunlight, short daylight hours and high temperatures, the cactus gradually becomes depleted and begins to wither and rot. In addition, during the dormant period (during the cold wintering from November to March), the cactus lays flower buds. A rested plant produces many young shoots and grows intensively with the onset of spring.
The second reason why a cactus rots is an excess of moisture.. It is very easy to flood a cactus both during the dormant period and even in the hot summer. In winter, the plant is not watered; in summer, the soil in the pot should dry out between waterings. Both those cacti whose homeland is the desert and those that grow in the forest and are accustomed to a humid climate cannot tolerate an excess of moisture.
Sometimes a cactus rots on top. It could be bacterial rot. In this case, even under good conditions (moderate watering, daylight hours 14 hours, temperature +12...+16 degrees in winter, up to +25...+28 degrees in summer), the rot spot will spread. You need to observe the plant for 2-3 days. If the stain grows, when you press on it, it becomes wet, and a viscous substance is released from under the skin - this is bacterial rot. The plant can no longer be saved; it must be removed from other flowers.
The cactus rots on top if it is frozen in winter. The plant may come into contact with cold glass. If the plant is frozen, it needs to be provided with normal care for wintering. The rotten area is cut out and dried until a dense crust forms on the stem. The plant will no longer regain its previous shape, but this cactus is used for grafting other ornamental varieties.
To prevent the cactus from rotting in winter from excess moisture, high temperature or lack of light, experts recommend organizing special boxes made of polycarbonate or glass, for example, an old aquarium. You can and should place an artificial lighting lamp there. Such boxes are placed as close as possible to the cold glass of the window or taken out to an insulated loggia (mandatory condition: the temperature on the loggia should not fall below +12 degrees. The temperature of keeping a cactus in winter depends on the type. Similar information can be found in reference literature.) Inside the box - greenhouses, a window close to the glass, the average daily temperature in winter will be lower than in the apartment.
The second reason why a cactus rots is an excess of moisture. In most cases, the cactus rots from the bottom. A sure sign is that the cactus turns yellow from below. Excess moisture in the soil is dangerous both in winter when the temperature is low and in summer when it is hot. Even when it’s hot, cacti are watered only after the soil has dried with a large amount of settled, soft water. In winter, watering is generally very rare, since the plant sleeps at this time.
What to do if the cactus is rotting from below? You need to do the following:
1. Remove the plant from the pot and wash it off the soil.
2. Next, the rot is cut off down to healthy tissue. You need to cut generously, since fungal micelles penetrate even healthy tissue. They are not visible, but after cutting and subsequent rooting, the cactus again begins to rot from below.
3. The cactus stem must also be cut on the sides, so the cut should resemble a slightly sharpened pencil.
4. After pruning, the cactus should dry out. You need to dry it in a bright place, but protected from sunlight. Dry the cactus cut until a thick crust forms on the cut. This may take 1-2 weeks. Some experts dry the cactus until roots form.
5. The dried cactus must be placed in a small pot with sand. The sand must be dry. Watering is carried out very sparingly and through a tray. Water should soak 1-2 cm of the bottom layer of sand. The plant is kept in a bright place without direct sunlight. In conditions of poor watering (when only the bottom layer of sand is wet), the cactus should take root very quickly.
The cactus' spines are falling off. What to do? The first reason why the spines of a cactus fall off is waterlogging of the soil. During the dormant period, when the plant has a cold winter, the soil in the pot is not watered or watering is very poor. If you water a cactus too much in winter, it begins to rot. One of the signs of overwatering of a plant is the falling of thorns, but in most cases the plant turns yellow.
During the period of intensive growth, the cactus consumes a very large amount of water, but it is watered only after the soil in the pot has dried. However, even in summer you can flood the cactus. For example, a large volume of soil for a small cactus. In this case, moisture accumulates in the soil, which is not occupied by roots. The result is that the roots rot and the thorns fall off. The second case is moderate watering at a low temperature and insufficient lighting. When it is cold and there is little light (the cactus is located in partial shade), all processes in the plant slow down, including moisture consumption. Under such conditions, even moderate watering can lead to rotting of the plant. Its thorns begin to fall off. A sure sign of insufficient lighting is that the cactus stretches out.
Another reason why cactus needles fall off is mealybug. A sure sign is a white, cottony coating on the stem of the plant. Treatment of cactus disease: treatment with Actelik according to the recipe included with the drug.
The cactus turns yellow on the bottom. What to do? Most cacti turn yellow at the base with age (mostly from 4 years). The bottom of the cactus becomes coarser and becomes covered with a cork coating, which has a yellow-brown color. This is normal if there are no ulcers under the cork coating and the bottom of the cactus has not become soft. Otherwise, rot develops on the plant.
There is a white coating on the cactus. What is this? This is a mealybug - a whitish, round-shaped arthropod. It settles in the root zone of the plant. If the infestation is severe, mealybug can be seen between the ribs of the cactus. A sure sign is a white coating similar to flour. At the same time, the stems slow down their growth, become depleted, and lose color. Measures to combat the disease: spray the stem with Aktara (solution concentration 4 g of the drug per 5 liters of water) and water the soil (concentration of 1 g of the drug per 10 liters of water). Carry out the treatment 4 times with an interval of 7-10 days.
Spots appeared on the cactus. Spots on a cactus can be of a very different nature. So, the most harmless spots that cover a cactus are sunburn spots. They appear if a plant, which was previously located in partial shade, is placed in direct sunlight. The second option is when forest plants are exposed to the scorching sun. How to treat a flower: it needs to be shaded and sprayed.
Brown spots on the cactus that look more like rust are the result of the activity of spider mites. Even after the cactus is cured of the disease, the rusty spots remain. When the plant is severely damaged, a thin cobweb appears. How to treat cactus disease? Treat with drugs, according to the instructions, from the following list: Actellik, Neoron, Fufanon, Apollo, Oberon.
