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In autumn, looking at the leaf fall outside the window, flower growers often mistake the massive loss of leaves in house plants as a natural process. But is this the norm for all of them?
Leaf fall is an adaptive adaptation in plants that contributes to their survival in difficult natural conditions.
Common pomegranate (Punica granatum)
A very important process of photosynthesis takes place in the leaves, in which light energy is transferred to the plant, and complex organic molecules - glucose, amino acids, glycerol, fatty acids - are synthesized from simple inorganic substances - water and carbon dioxide. This is how the leaf feeds the plant. For this, in addition to water and carbon dioxide, sunshine of sufficient intensity and a temperature of at least + 5 … + 10 o C. are needed. But, like any living organ, the leaf requires certain expenditures of energy and nutrients for its maintenance. If unfavorable conditions develop, when the plant is no longer able to fully carry out photosynthesis, it is forced to abandon all the leaves or their parts so as not to waste energy and reserves on maintaining organs that are already useless to it.
The annual decrease in daylight hours in northern latitudes in autumn, cooling, cooling of the soil (which makes it impossible for the roots to absorb water), have developed a mechanism for the annual shedding of leaves in the plants growing there. For them, autumn leaf fall is a normal, natural and obligatory process, such plants are called deciduous. When growing them at home, it is unacceptable to pick off the still green leaves. It can be transferred to a dark place only after the leaves have completely naturally subsided.
Deciduous plants most commonly grown at home: ficus carica or fig (Ficus carica), common pomegranate (Punica granatum), Indian lagerstroemia (Lagerstroemia indica), ginkgo biloba (Ginkgo biloba), black mulberry (Morus ni gra), hibiscus Syrian (Hibiscus syriacus), palm-shaped maple (Acer palmatum).
After dropping the foliage in the fall, place them in a cool place (+ 5 … + 10 o C), it is possible in a cellar or basement without light. Plants usually die without winter rest for several years.
palm maple (Acer palmatum), bonsai
Semi-leafy (or semi-evergreen) plants are called plants that do not regularly drop leaves, but only when unfavorable conditions develop, so they have adapted to possible changes in external conditions. Such plants recover rather easily with the onset of favorable conditions again.
Indoor semi-leafy plants and methods for their wintering
Bougainvillea (Bougainvillea), growing naturally in warm climates, sheds leaves when drought occurs. At home, leaf fall occurs at temperatures below +10 o C, which limits the flow of water. So that the plant does not deplete with a lack of light, it is better to lower the temperature to + 10 … + 12 о С in the autumn-winter period, do not allow cooling below +5 о С. In this case, partial or complete leaf fall can be observed, which will not harm the plant. At higher temperatures, bougainvillea starts to grow, so it needs bright light in the warmth.
Rose (Rosa) in favorable tropical conditions remains evergreen, but when the temperature drops to +5 o C, it will shed its leaves. It is preferable for her to arrange a cool wintering at a temperature of + 10 … + 15 о С in bright light. In cold conditions, 0 … + 5 о С, after leaf fall, you can keep it in a dark room.
The sacred ficus (Ficus religiosa) and the rough ficus (Ficus asper a) in nature react with leaf fall to drought, which cannot be allowed at home. In case of loss of leaves, urgently put the plant under illumination and normalize the watering regime.
Mrs. Thomson's Clerodendrum (Cler o dendrum thompsonae) partially sheds leaves when there is a lack of light and from dry air. In winter, keep the plant in bright light at a temperature of 15 to C moderate watering.
Indoor evergreens in autumn
In evergreens x plants, the replacement of old leaves also occurs, but it is gradual, throughout the year. Under unfavorable conditions, this process can accelerate, which is why a more significant loss of leaves is observed in autumn. Strong leaf fall in evergreens is not an adaptation mechanism; it always serves as a signal for early measures to improve conditions in order to prevent their death. This group is difficult to recover from the loss of most of the leaves.
Reasons for falling leaves in autumn in evergreens:
Lack of light when kept warm. If little energy is produced (in conditions of a lack of light), but a lot is spent (in a warm room), the plant is gradually depleted, sometimes "eating" itself. And for the sake of preserving the top with the growth point, the plant is forced to shed some of the leaves, first the lower ones, and then the rest.
- Cooling the coma, watering with cold water leads to the loss of the ability to absorb water by the roots, the plant begins to wilt with a damp coma, and leaf fall may begin. This phenomenon is often seen in the fall and winter, when the pot is on a cold windowsill or on the floor. Sometimes the difference between the temperature at the bottom of the pot and in the middle of the room is more than 10-15 degrees. Cooling the coma to +15 o C - for some, and to +10 o C - for many domestic plants is already critical. Use water no colder than the room temperature for watering. It is unacceptable to cover plants with ice or water with cold water.
- An incorrect watering regime also leads to a loss of turgor by the leaves, which provokes leaf fall. Insufficient watering will directly lead to drought, and excessive watering will lead to disease and poor functioning of the roots, they cannot absorb water without oxygen, which will also result in a lack of water in the plant tissues. In autumn, with a decrease in ambient temperature and a decrease in illumination, the growth rate decreases, and, accordingly, the need for water decreases. It is very important to prevent waterlogging, in time, according to changes in conditions, to reduce the frequency and abundance of watering.
- Sharp temperature fluctuations, strong sudden cooling, cold drafts often lead to leaf fall.
- Dry indoor air during the heating season. In some plants, stomata close to prevent too much water loss through evaporation at low air humidity. Carbon dioxide ceases to enter the leaf, and this leads to a violation of photosynthesis.
- Tick infestation as a result of poor living conditions. Their rapid reproduction will be facilitated by dry air and other reasons leading to the loss of turgor by the leaves (cooling of the roots, overdrying or waterlogging, salting of the soil) - weakened cell walls become easily accessible to the tick. And the higher the room temperature, the faster the mite multiplies. Sucking out cell sap, parasites cause early yellowing and death of leaves.
- Reduce the temperature of the content, for subtropical species it is + 10 … + 14 о С, for thermophilic tropical species it is about + 16 … + 18 о С. This will slow down the metabolism of plants, reduce energy losses, and reduce the activity of ticks.
- Make sure with a thermometer that the roots are not overcooled.
- Adjust the frequency and amount of watering according to the environment and plant requirements.
- To feed - the reason for falling leaves is not starvation. Diseased plants cannot fully assimilate the introduced nutrients; they will accumulate in the soil and can cause poisoning.
Evergreens often prone to leaf fall
Azalea (Rhododendron, Azalea)
Azalea (Rhododendron, Azalea). Indoor varieties are not deciduous, the upper dense leaves in the form of a whorl on the crown of the shoot remain for the winter. Leaf fall can begin with overdrying or waterlogging of the soil, warm winter content, from watering with cold water or icing, from dry air.
Chinese hibiscus (Hibiscus rosa - sinensis) - a massive loss of leaves begins from a lack of light, a spider mite defeat, from hypothermia.
Codiaeum variegated (Codiaeum variegatum) - its leaf fall begins from sudden changes in temperature, cold drafts, lack of light, improper watering.
Ficus benjamina (Ficus benjamina, Ficus nitida), rubber ficus (Ficus elastica), small-fruited ficus (Ficus microcarpa), dull ficus (Ficus retusa) will begin to shed leaves with a lack of light, improper watering and hypothermia of the roots.
Common myrtle (Myrtus communis) will respond by massively dropping leaves to high temperatures, improper watering (overdrying or waterlogging) and lack of light.
Citrus crops (Citrus) - leaf fall can begin during wintering in a warm room, especially in conditions of lack of light, as well as with sharp, more than 10 degrees during the day, temperature changes.
At the onset of leaf fall, normalize the conditions of detention:
Place the plant under light.
What not to do when falling leaves in autumn and winter:
It is not worth replanting - this is unnecessary and unnecessary stress for the plant. Usually, the transplant in this case ends with the death of the plant.
Photo by Maxim Minin, Rita Brilliantova and from the GreenInfo.ru forum