Dieffenbachia is a fairly common indoor plant. Caring for him is not complicated. However, gardeners are interested in why the leaves of Dieffenbachia turn yellow , what to do in this case, how can the plant be helped? In this article we will try to answer these questions.
But first you need to find out why the leaves of Dieffenbachia turn yellow, what are the reasons that contribute to the development of this ailment. They may be different. Conventionally, experts divide them into three categories: pests, diseases, improper care.
Dieffenbachia: leaves turn yellow. What to do?
Dieffenbachia is a light and rather unpretentious plant to care for. However, it is accustomed to a humid tropical climate, and therefore makes a number of maintenance requirements. First of all, you need to know the grower in whose house Dieffenbachia grows: the leaves of the plant turn yellow often with insufficient lighting, improper watering and soil selection, low temperature.
Illumination
This indoor flower prefers diffuse lighting (2500-2700 lux), does not tolerate direct sunlight. At the same time, she needs additional illumination in the dark. Daylight hours with its help should be at least 10 hours. The bright sun causes a burn of leaves, after which brown dry spots appear on the surface of the leaf plate, which surround large yellowed areas.
To return the plant to its attractive appearance, the affected leaves must be cut off - they will not be able to recover. Inadequate lighting can adversely affect the overall color of the leaves. In a plant located in the shade, on the north window or in the back of the room, the leaves may initially turn pale, and then they will acquire a light yellowish tint. But to cope with this trouble is simple enough: just rearrange the flower in a more illuminated place - and Dieffenbachia will again delight you with a bright color.
Watering
Another extremely important factor that many beginner gardeners neglect. Excessive moisture does not tolerate dieffenbachia. The lower leaves turn yellow in this case due to loss of roots. Yellowness in this situation is the last stage, which is accompanied by blackening of the stems. Florist error - waterlogging of the soil.
When the soil between the irrigations is not allowed to dry, aeration is disturbed, the roots suffocate and rot. Accelerates this process the development of algae on the surface of the soil, the walls of the pot, as well as a sharp awakening of fungal spores. Is Dieffenbachia doomed in this case too? The leaves turn yellow in this case, giving you a signal that the plant needs urgent help. At the initial stage, it is quite easy to save. Transplant the flower into another soil, having previously cleared the decayed roots.
The need for such a transplant is indicated by several external factors:
- the surface of the soil becomes slime;
- a greenish coating appears;
- during subsequent watering (even if the earth has dried up) an unpleasant odor appears.
To avoid the development of rot, a good drainage layer must be formed at the bottom of the pot, which will save the plant from an excess of moisture, and the pot must be selected according to the size of the root system.
Sometimes gardeners say that, despite the fact that Dieffenbachia is not watered too abundantly, the leaves turn yellow. The reason may be overdrying. It is less fatal for the plant, but sometimes it can also cause its death.
And another mistake that many lovers of indoor plants make is watering with hard water. It can cause the development of leaf chlorosis: they turn pale, and then turn yellow. For the prevention, as well as the treatment of this disease, the plant should be watered only with soft, standing water. From time to time, Dieffenbachia needs to be nourished with iron chelates.
Why do dieffenbachia yellow lower leaves? Soil selection and top dressing
This plant loves moisture- and breathable, slightly acidic soils, with high levels of humic acids, phosphorus, potassium and nitrogen. If the soil is chosen incorrectly, in violation of the salt balance, then the roots will not be able to perform their functions, nutrients will become inaccessible to the flower.
This will immediately demonstrate to you with its appearance Dieffenbachia - leaves turn yellow (mainly lower, adults). Moreover, the plant will slow growth, and a new growth will be underdeveloped and weak. When the soil contains insufficient amounts of potassium and phosphorus, or with an excess of nitrogen in the flower, the upper leaves turn yellow. Therefore, top dressing should be strictly dosed. For this, balanced complex fertilizers for deciduous ornamental plants are most suitable.
Temperature mode
Dieffenbachia is a thermophilic plant. She needs moderate temperatures throughout the year. It can tolerate a short-term decrease in temperature to +10 ... + 12 ° C, however, after the stress, the lower leaves will necessarily turn yellow and fall.
But temperature drops and drafts categorically do not accept Dieffenbachia. The leaves turn yellow in this case, first along the edge, and then begin to dry out. This is a very common phenomenon, which is called necrosis, it is well known to many gardeners.
Pests
Like most houseplants, Dieffenbachia is invaded by pests. This is, first of all, aphids, scale insects, thrips, mealybugs, and the spider mite causes its biggest problems. All these pests suck out juice from shoots and leaves, which leads to depletion of the plant, its lag in development and deformation of young shoots.
Often yellowed leaves signal the invasion of uninvited guests. This is especially often manifested when a plant is infected with a spider mite. Initially, groups of small yellow dots appear on the outer side of the leaf plate, which grow quite quickly, discoloring almost the entire sheet. Moreover, from within it (and the petiole) is covered with a thin cobweb along which barely noticeable brown “points” move. These are ticks.
Infected leaves cannot be restored, they should be trimmed, and the whole plant should be washed well under warm water (about +40 ° C), previously protecting the ground from excessive moisture. If this is not enough for a complete cure, then the procedure is repeated or the plant is treated with a special chemical preparation, for example, Fitoverm or Aktellik.
Disease
One of the most serious causes of the appearance of yellow spots on the leaves of dieffenbachia is viral, fungal and infectious diseases. They are not always easy to identify, nevertheless we will describe the most common ones.
Fungal diseases
Anthracnose - on the edge of the sheet and next to it appear black-brown large spots with a yellowish border. Gradually, the leaf dries and dies.
Root rot - dark spots appear on the root neck, on the roots you can see a light gray mycelium. As the disease develops, the leaves turn yellow, fall, and the plant dies. The fungus is transported through the soil and develops in a new place with excessive watering and high humidity.
Leaf spotting - small brown spots with an orange border appear on leaf blades. Gradually they grow and cover the entire surface of the sheet. Infection occurs through the remains of diseased leaves and water. The disease is exacerbated by waterlogging.
Preventive measures in the fight against fungal diseases include:
- use of high-quality soil;
- compliance with all requirements for plant conditions.
If the first suspicious signs of the disease are detected, the plant must be treated with a systemic fungicide, for example, Fundazolum or Vitarosom.
Bacterial diseases
The most dangerous of them is bacteriosis. It leads to the death of the plant. On the infected flower, watery areas with clearly visible borders appear on the leaves and stems. Gradually they turn brown or turn brown. The disease is transmitted from one diseased plant to another through damage to the stems. The treatment for this disease has not yet been developed.
Viral diseases
Bronze - yellow roundish or annular spots appear on the leaves. Gradually affected leaves fade, although they remain on the branches.
Viral mosaic - on a leaf plate you can immediately see numerous rounded spots of dark green color with a bright middle. The plant stops in development.
Viruses are transferred from an infected plant to a healthy one either through direct contact or by pests: aphids and thrips. It is impossible to cure the plant, so it is destroyed.
Leaf aging
Dieffenbachia belongs to the fast-growing plants, therefore, it is typical for the exposure of the stem. Do not worry if the flower has turned yellow and one bottom leaf has fallen, and this unpleasant defect has not spread to the rest of the plant. This shows that a natural process of aging and dying off occurs.