Dieffenbachia is an unpretentious perennial deciduous houseplant native to countries with tropical climates. For all its decorativeness, the sap of the plant is poisonous to humans and one must be very careful in any contact with this deciduous crop. Look after dieffenbachia easy and years of experience in floriculture is required. But it is still necessary to strictly observe all the preferences of the flower regarding watering, light, heat and soil composition.
Many people face a problem when the leaves of Dieffenbachia turn yellow. And although there can be a lot of reasons, they can be conditionally divided into three main groups: violation of conditions of detention and rules of care, the appearance of diseases, the invasion of pests.
Violation of the rules of care for dieffenbachia
Incorrect lighting
For dieffenbachia, a long daylight hours (at least 10-12 hours) throughout the year are very important. Lighting should be diffused, culture should be protected from direct sunlight. On short light days in autumn and winter, additional lighting with phytolamps or fluorescent lamps will be required. The most favorable illumination level is from 2500 to 2700 lux.
Bright light and direct rays of the sun, when they hit the leaves, leave a burn in the form of dry spots of a brown hue against a background of emerging yellowness. Such leaves can no longer be restored, and it is recommended to remove them. Insufficient lighting will also negatively affect the decorativeness of dieffenbachia. This can happen if the crop is grown on a north-facing windowsill or in the back of a room away from a light source. At first, the leaves will turn light green, then almost white, and soon begin to turn yellow. If the plant is promptly rearranged to another place with good lighting, then the normal green color of the leaves will gradually recover.
Unsuitable temperature
For thermophilic dieffenbachia, sudden temperature changes, regular drafts and cold ventilation are undesirable. This can cause yellow and dry leaves to appear. The optimum room temperature throughout the year is 20-25 degrees. Even a short-term drop in temperature to 10-12 degrees will lead to yellowing and shedding of the lower leaf part. Although Dieffenbachia will not die after such temperature jumps, its appearance will lose its beauty. The leaves will still fall off even when the temperature returns to normal.
Violation of watering rules
The condition and color of the dieffenbachia leaf mass depends on the volume and frequency of watering. Yellow leaves can be due to the regular excess of moisture in the soil. They talk about rotting of the root part, which begins as a result of waterlogging of the soil. The soil should dry out a little before the next watering, the soil should remain light and breathable. And an excess of irrigation water leads to compaction of the substrate and does not allow the roots to breathe.In addition, excess moisture leads to the appearance and spread of a large amount of fungus in the flower container, algae begin to develop on the surface of the soil.
At the first signs of decay of the root part, it is recommended to urgently remove the flower from the pot, replace it and the flower soil, and carefully examine the roots, rinse, remove diseased parts and treat the cut sites with charcoal. The new flower container must match the size of the dieffenbachia root system. A good drainage layer is necessarily formed at its bottom. The reason for an emergency transplant is a greenish coating on the surface of the soil in the pot and an unpleasant odor from the moist soil.
No less dangerous for the culture and lack of moisture with excessive overdrying of the soil mixture. If watering is untimely, the leaves of the flower turn brown and dry out slowly.
When watering, it is very important to use only soft water, which has settled for 1-2 days. From hard water, the leaves of Dieffenbachia turn pale and turn yellow.
Incorrect soil composition and fertilization
The soil should be slightly acidic in composition, light, loose, with good water and air permeability and a high content of potassium, phosphorus, nitrogen and humic acids. This soil mix can be purchased at any specialty store. Another (inappropriate for this culture) composition and density of the soil will lead to a lack of nutrition for the root part. This will affect the external characteristics of old and young foliage. Adult leaves in the lower part of Dieffenbachia will turn yellow, while young ones will grow slowly and develop poorly.
The development of dieffenbachia directly depends on the volume and frequency of feeding, as well as on the amount of such useful elements as nitrogen, potassium and phosphorus. Experienced flower growers advise using complex fertilizers strictly according to the instructions and for the intended purpose, since yellowing of the leaves can begin not only due to a lack of potassium and phosphorus, but also with an excess of nitrogen.
Pests
The main pests of dieffenbachia are scale insects, spider mites, aphids, thrips, mealybugs. Their main food is the juice of shoots and leaves. The most common source of lag in room dieffenbachia in development and the appearance of yellow leaves is a spider mite. First, the smallest dots of yellow appear on the back of the sheet, which every day occupy an increasing area and discolor it. Also, the presence of a tick is confirmed by numerous thin threads of a cobweb.
Control measures at the initial stage - a warm shower of the whole plant, at a later date - treatment with special chemicals (for example, "Fitoverm" or "Actellik").
Diseases
Fungal diseases
Root rot occurs under conditions of constant high soil moisture and abundant watering. First, a slight yellowing appears on the leaves of Dieffenbachia, then their wilting occurs and the flower dies. This means that a fungus has appeared in the root of the plant, which affects the entire root system.
Leaf spot begins with infestation from other indoor plants and is fueled by excess moisture during watering. At the initial stage, the leaves are covered with brown spots, surrounded by an orange border. Very quickly, the spots grow in size and destroy all the leaves.
Anthracnose is a consequence of acidification and waterlogging of the soil in a pot, as well as parts of an infected indoor flower that have fallen into the ground. With this disease, the leaves are covered with large spots of black or dark brown. Very soon the leaves dry up completely and dieffenbachia dies.
Fusarium is a disease that is transmitted to a healthy plant from a sick plant through an infected potting soil mixture or when the flower containers in which they are grown are close. The fungus attacks the root system. An insufficient amount of potassium in the soil and prolonged overdrying of the earthen coma "helps" to develop the disease.
Recommended preventive measures are the use of a high-quality soil mixture, strict adherence to all the rules for keeping and caring for dieffenbachia, treating the flower with special preparations and solutions at the initial stage and at the first unpleasant symptoms.
Viral diseases
Withering shoots, as well as yellow spots on the leafy part in the form of a circle or ring - this is the beginning of a viral disease called bronzing. Dieffenbachia leaves are struck very quickly, but they do not fall off, but remain on the shoots in a drooping state.
If dieffenbachia has stopped growing and developing, and a large number of rounded spots with a light green center and a dark green border appear on the leaves, then the plant is infected with a viral mosaic.
Viral diseases, unfortunately for indoor plant lovers, cannot be cured. Even in the early stages of the detection of the disease, it is recommended to urgently remove the culture so that the rest of the flora in the room does not become infected.
Dieffenbachia can get infected from a diseased flower, being in the immediate vicinity of it. Also, pests that easily move from one plant to another (for example, aphids and thrips) are common distributors of viral diseases.
Bacterial diseases
One of the most dangerous diseases that does not respond to any treatment, and from which indoor plants die, is bacteriosis. Methods of infection - from a sick plant to a healthy one through infected stems, leaves, soil. To preserve healthy indoor flowers, it is urgent to isolate the diseased specimen and destroy it. Signs of the onset of the disease are watery areas of the stems or leaves and the acquisition of a brown or brown tint in the future.
If there are numerous reasons for the yellowing of the leaves in Dipenbachia, there is one more, which should not cause panic or excitement in lovers of indoor flowers. This reason is natural and applies to all plants that have survived to a certain age. The maturation or aging of a fast-growing flower can manifest itself in a slight exposure of the stem and the fall of 1-2 yellow leaves in the lower part of the flower. If this ends the dropping of leaves and the "signs of disease" have not spread to other plants in the house, then there is no need to worry.
