Cactus diseases are most often caused by bacteria, lower fungi, mycoplasmas and viruses. Some of the diseases are quite simple to cure, but a greater number of them, even with timely treatment, can lead to the death of a cactus, and they most often affect rare and expensive succulents.
Common Cactus Diseases
Particularly dangerous are those diseases that occur without any symptoms. Since it is very difficult to detect them, and without timely and proper treatment, the plant simply dies.
Various cactus diseases
But an attentive florist, who constantly cares for his green pets, can still notice that something is wrong with the plant.
It should alert:
- weakening or complete absence of growth, especially during the period of active vegetation in the spring;
- the appearance of wrinkles on the stem or a change in its color;
- lack of flowering or dropping buds;
- dying and drying of shoots;
- formation of cracks and various spots on the stem.
You can often notice that dry rot appeared on the cactus, mold is the cause of its formation. If the cactus begins to dry and it has dull stems, this is a clear sign that it was struck by dry rot.
To get rid of such a disease is quite difficult, often the diagnosis is made already at the last stage of the disease. In order to prevent the formation of dry rot, it is worth using various fungicides as a prophylactic. It is best to process the plant 3-4 times a year.
Mamillaria, or black rot, manifests itself in the form of small putrid spots of black color. As a rule, they form in the areoles and provoke the subsequent falling of thorns from them. This disease can occur after a plant is transplanted into soil contaminated with spores. Also, black rot may appear subsequently overmoistening the soil or insufficient lighting, especially in winter, or as a result of mechanical damage.
Fungal disease, as a rule, affects the stems of young plants. Due to the defeat, the stems are very bent, and the cactus may fall, a velvety green coating and mold appear on its surface. This plaque is nothing but ripening spores of fungi. To kill young cacti, the fungus will need only a few days.
This disease develops well with low air temperature and very high humidity. There is no point in saving a plant from such a disease, since the infection of healthy tissues occurs very quickly and can rot the entire root system and trunk.
Rhizoctonia or wet rot very often develops on young seedlings or cuttings. The disease develops very quickly, spreading from the roots to the top of the plant, and leads to its death. There is a small chance to save the plant from such a disease if, immediately upon its detection, all affected areas are removed and the remaining healthy parts of the plant are transplanted into a new steamed substrate.
With brown rot, darkening forms on the stems, which come from the base or from places where there are untreated wounds. Subsequently, the trunk softens, a viscous mass forms inside it, which resembles jelly.
Reasons why the cactus rotted:
- Excess moisture in the soil. It happens with excessive watering and cold air temperature in the room.
- High humidity indoors.
One of the reasons why thorns begin to fall out of a cactus is a strong overmoistening of the soil. In the dormant period, when the flower needs cool air, the earth in the pot should be watered very rarely or not at all.
Important! If the cactus is abundantly watered during the winter period of rest, it will begin to decay the root system and the thorns will fall off.
During the period of active vegetation, succulents need abundant watering, but it is necessary to water it only after the soil has completely dried in a pot, since the cactus can be heavily flooded in hot summers. If moisture constantly accumulates at the roots, this will lead to their decay and the fall of all the thorns. It is necessary to treat such a problem by replanting a flower in a new soil and establishing a watering regime.
Stains on the cactus are caused by various viruses and bacteria. And the reason for their appearance is the improper conditions of the plant. First of all, this is the influence of cold air, if in the winter a cactus stands on the windowsill of a frequently ventilated window and this is in the zone of constant drafts. Also, high humidity in combination with cool air in the room adversely affects the plant. To save the flower from spotting, you need to rearrange it to a more comfortable place and establish proper care.
Often, spotted rust appears on the cacti, which affects the stem in the form of rusty crusts or stains. The cause of this disease may be sunburn or cold water falling on the stem, as well as a sharp decrease in room temperature. If such spots have already appeared, it is rather difficult to remove them, since they begin to spread to other parts of the stem and become more and more extensive.
Spotting rusty and yellow.
The cactus acquires a yellow color with an insufficient amount of nutrients in the soil, as well as with a bacterial or viral disease. As a rule, yellowing of the cactus begins with the tips of the shoots and the top of the plant. If the succulent has turned yellow all over, it can be caused by a virus called jaundice, and there is no cure for this disease. It can go very quickly, or last for several months or even years.
This disease is caused by fungi of the Fusarium family, very often it affects jointed succulents. The spread occurs gradually, first the fungi hit the roots, then they get into the conductive system, reach the top, and the cactus withers. If pink or purple plaque is visible on the stems of the cactus, its stems become wrinkled and begin to lean toward the bottom, this is a clear sign of fusarium. With a cut on the stems, you can notice the maroon-brown conductive vessels.
Excessive soil moisture and increased humidity in the room contribute to this disease. What to do if the cactus begins to rot - as soon as possible, remove the flower from the pot and cut off the entire rotted part of the trunk, treat the cut with charcoal, dry it and root again.
Important! Spores of the Fusarium fungus easily penetrate any wounds and damage on the stems.
With excessive watering and low temperature in the room, the likelihood of this disease increases.
If white plaque or dots similar to fluff is visible on the cactus, this is a sure sign that the mealybug has attacked the plant. The reason for the appearance of this pest is considered improper care, infection from another plant or penetration through infected soil.
There may be several treatment options depending on the type of disease.
How to save a cactus if it began to rot from below, the sequence of actions:
- Cut off all roots that are severely damaged or completely rotted.
- Rinse the remaining healthy roots in a solution of potassium permanganate.
- Sprinkle with sulfur powder or charcoal crumbs.
- Dry for 2 to 3 days by hanging in an upright position.
- Take a new disinfected pot, pour steamed soil into it and plant a cactus.
- After planting, the plant does not need to be watered at all for 3-4 weeks.
In order to avoid such a problem in the future, it is necessary to adhere to all watering rules.
Additional Information! Fungi have different modifications, but each of them will progress more strongly if the flower is in a cool room, and on the street at this time it is cloudy or raining.
If the root of the cactus has rotted, what to do in this case:
- Cut off the rotten piece and look carefully so that the cut stays healthy and clean.
- The stalk needs to be slightly “sharpened”, like a pencil, so that later it would be more convenient to plant it in the ground.
- Treat the slice with crushed activated carbon.
- Allow to dry well by securing it in an upright position or putting it on a plastic cup.
- Wait until the young roots sprout. The process is quite lengthy, it can take more than ten days.
- When the roots appear to plant a seedling in the ground for cacti.
- Water only through the pan. 10 minutes after watering, drain from it all the water that the glass.
The next time you can water only after 3-3.5 weeks.
Another way to reanimate a cactus if it rotted:
- Cut off the entire rotted part of the cactus.
- Dry for 3-4 days, during which time the cut should be tightened.
- Treat with a root growth stimulator and put in a glass of water. Water needs so much that it covers a slice of 2-3 centimeters.
- After about 1-2 weeks, new roots will appear, when they reach 1 cm in length, the plant can be transplanted into a new prepared soil.
A cactus transplanted in this way cannot be fed with fertilizers for one year.
If there are pests or diseases, it is worth transplanting the flower into a new pot with new soil.
Transplanting into a new pot
The cactus rots from below, what to do, in this case:
- Shake out the cactus from the old pot, carefully inspect the root and the trunk itself.
- Dried and damaged roots should be trimmed, if the stem is damaged, it must be cut to a healthy tissue, and sprinkled with crushed activated carbon.
- Next, the flower must be washed well in hot water (50-55 degrees), adding a fungicide or insecticide to it.
- Dry for 3-5 days in the sun in an upright position and with well-spread roots.
- Plant in the ground by placing the stem vertically in a pot and sprinkling the roots with earth. It is very important to ensure that the earth does not reach above the root collar.
After such a cactus transplant, it must be kept in partial shade, without watering for about 3-5 days.
Note! When planting, it is important to arrange good drainage in the pot and add a lot of sand to the soil.
Cropping affected areas
How to save a cactus if it is affected by fungal rot:
- If the cactus trunk is affected, cut off the lesion with a knife and treat with sulfur.
- If the top is affected, then it must be cut to a healthy tissue, and the plant itself should be used as a stock for vaccinations.
- If rot on a cactus - disinfect the wounds with charcoal or activated charcoal, or treat with brilliant green.
During the period of treatment for fungi, it is necessary to exclude any spraying with water, it is better to use a fungicide solution for this purpose.
With dry rot, brown spotting and late blight, it is necessary to periodically (1-2 times a month) treat plants with phytoncides and insecticides.
With brown rot, if the cactus has become soft and watery, what to do:
- Heal all injuries on the cactus trunk.
- Adhere to the correct care regimen.
- Treat the plant with fungicides once every 1-2 weeks.
Further cactus care
After the plant is cured, so that in the future it does not have any health problems, it is necessary to create favorable conditions.
Temperature and humidity
For cacti, the birthplace of which is the desert, it is necessary to provide enough sunlight. They feel good when placed in direct sunlight, but in the summer in the midday heat it is still better to shade them so as not to provoke a burn.
Summer temperatures are preferable to 26-28 ° C heat. Humidity they require at least 40-50%. preferred air temperature in winter is not more than 15-18 ° C heat. Most of the varieties (except for densely pubescent ones) will easily suffer a decrease in temperature to + 5 ° C. For people from the tropics, a bright but diffused light and humidity of at least 60% are required.
In winter, cacti stay in a dormant period and hibernate. During this period, plants do not need frequent watering. Watering cacti is not more than once every two weeks, and in small quantities. With the advent of spring, the amount of watering is gradually increased, and in the summer they are watered quite often (every 3-4 days). Since October, watering should again be limited. Water should be used only warm and purified.
How to understand that a cactus has withered after winter
First, dry spots appear on the stem, the flower loses its decorative qualities, and eventually dies. If the cactus grows even a little, brand new thorns appear on it and all green tissues remain alive, it is in good condition. If the stem is hard, and the soil in the pot is very dry, then the cactus clearly dies from drought, especially if it is located in the zone of active sunlight.
Watering through the pan
For cacti native to the desert, the soil needs light, loose, moisture-permeable. For tropical succulents, the soil needs airy, light and slightly acidic. The soil should have good drainage in the form of small pebbles, expanded clay or crushed bricks. The soil must contain sand, peat and charcoal.
Diseases of cacti and their treatment at home require special attention, since his future fate will depend on timely assistance to the green pet. In order to cope with diseases and pests, you must always respond quickly, and even better to stop their appearance, properly caring for your beloved prickly friend.