With the onset of autumn, most trees and shrubs shed their leaves in preparation for wintering. Before this process, a change in the color of the leaves is observed. But sometimes it happens that the leaves remain on the branches even when cold weather sets in. Let's find out together why this happens, what it can lead to and how to help the trees.

The role of leaves in the life of a tree

The most the main role foliage - the formation of organic products. Flattened sheet plate perfectly absorbs sunlight. The cells of its tissue contain a large number of chloroplasts, in which photosynthesis takes place, resulting in the formation of organic substances.

Did you know? Throughout life, plants evaporate a large amount of moisture. For example, an adult birch loses up to 40 liters of water per day, and an Australian eucalyptus (the most tall tree in the world) evaporates more than 500 liters.

The leaves of the plant also remove water. Moisture enters them through a system of vessels that stretch from the rhizome. Inside the leaf plate, water moves between cells to depressions, through which it subsequently evaporates. This is how the flow goes mineral elements through the whole plant. Plants can adjust the intensity of moisture output on their own by closing and opening the stomata. If moisture needs to be preserved, the stomata close. This mainly happens when the air is too dry and has high temperature. Also, through the leaves, gas exchange occurs between plants and the atmosphere. Through their stomata, they obtain carbon dioxide (carbon dioxide) necessary for the production of organic matter, and release the oxygen produced during photosynthesis. By saturating the air with oxygen, plants support the vital activity of other living beings on Earth.

What trees shed their leaves for the winter

Leaf fall is a natural stage in the development of most plants. This is how nature intended, because in the naked state, the surface of evaporation of moisture is reduced, the risk of branch breakage, etc. is reduced.

Important! Leaf fall - vital required process, without which the plant can simply die.

At different types Trees dropping leaves takes place in different ways. But the following crops shed their leaves every year:

  • poplar (begins to drop leaves at the end of September);
  • Linden;
  • bird cherry;
  • birch;
  • oak (leaf fall begins in early September);
  • mountain ash (loses leaves in October);
  • apple tree (one of the last fruit crops that shed their leaves - in early October);
  • nut;
  • maple (can stand with leaves until frost);
Remain green throughout the winter coniferous plants. With a short summer, the living conditions for the renewal of leaves every year are extremely unfavorable. That is why there are more evergreen species in the northern regions.

Did you know? In fact, conifers also drop needles. Only they do it not annually, but once every 2-4 years, gradually.

Reasons why leaves do not fall

Leaves that have not fallen in autumn indicate the incompleteness of the tree growth stage. This is typical for the most part for cultures of southern or Western European origin. They are not adapted to short summers and need a long and warm growing season. However, even winter-hardy crops can stay through the winter with green foliage.

This situation may arise in the following cases:

  1. There was a glut of nitrogen-containing fertilizers. They stimulate the growth process.
  2. A dry summer turned into a rainy one cold autumn. In this case, frequent watering only exacerbates the situation.
  3. The climate is not suitable for this variety. Perhaps the plant did not have time to fully complete the development phase.
  4. Wrong cut. If this work is done illiterately and out of time, it can provoke the rapid development of new shoots and leaves.
As a rule, all these factors lead to the fact that the plant enters wintering exhausted, with underdeveloped sprouts and with a delay in leaf fall. In addition, pathogens remain in the leaves various diseases, which leads to such consequences as frostbite or burns of fragile branches.

Important! Diseased foliage negatively affects the condition of the whole plant, reduces yield and reduces resistance to pests.

How to help and what to do

Specialists and experienced gardeners know that even trees unprepared for wintering can be helped. First of all, it is necessary to develop resistance to frost. For this you need:

  1. To sniff (remove) foliage. This process is carried out by running the palm of the hand along the branches from the bottom up, separating the dry and frail leaves. You can't force them to break.
  2. Whitewash the central branches and trunk of the tree. This procedure must be performed before frost.
  3. Create a rhizome thermal cushion. To do this, the first snow is trampled down, and a mixture of peat and sawdust is poured on top. The next fallen snow is also trampled down.
  4. Limited feeding. In autumn and late summer, only potash-phosphorus fertilizers can be applied and the tree should not be overfed.

 In early spring, plants that have stood with foliage on branches all winter will need to be fed with potassium sulfate, and in summer they will need to be sprayed with a pink solution of potassium permanganate. Thus, the process of preparing trees should begin in advance so that they do not stray from the cycle laid down by nature. Only in this case, the tree will meet strong frosts, and the next season will give a good harvest.

Almost all conifers are evergreens, but there are exceptions among them: some species shed their needles for the winter. These include swamp cypress and larch.
Taxodium, swamp cypress - large coniferous trees that grow in damp places and forest swamps in the southeastern United States. For us so far exotic plant and you can meet him in the parks south coast Crimea. Although swamp cypress seedlings appear in our garden center. But larch is well known to us.

European larch

European larch is distributed throughout Europe. It is not demanding on soils. Frost-resistant, resistant to urban conditions. This larch is durable, lives up to 500 years or more. A feature of the larch is that it is a deciduous tree, that is, the leaves fall off for the winter, and in the spring it has new green needles.
European larch is a very large plant. Individual specimens reach a height of more than 50 m and a width of up to 15 meters. The shape of the crown is regular, cone-shaped. For such a tree on your site you will need a lot of space. European larch is planted in arrays, groups, in alleys, in rows.
Despite the fact that European larch is a fast-growing tree, many people want to immediately plant a ready-made tall tree. This is not a problem, in the garden center large-sized larches are dug out with a clod of earth and packed in burlap and netting (if necessary). In the transplantation and delivery of such a plant, a special technique is used. If the size of the plot is small, then the growth of the tree can be restrained by regular pruning or compact varieties can be chosen. Very beautiful larches with a weeping crown shape.

matesequoia

This is a deciduous coniferous tree up to 40 m high with a trunk diameter of 2.5 m. The crown is slender cone-shaped. The barrel at the bottom has many recesses and looks very impressive.
The needles are 1-3 cm long, 2 mm wide, at first bright light green, then darkens in summer, before falling off in autumn it becomes depending on location and weather conditions pale yellow or light pink to ruby ​​red and reddish brown. The needles are extremely soft. They grow late - by the end of May, and fall off in early November.
Metasequoia is shade-tolerant, but develops better in open areas. It grows quickly, heat-resistant and frost-resistant down to -30°C, wind-resistant, not demanding on soils, but prefers well-drained, fertile and moist, resistant in urban conditions. In China, it grows successfully on the streets and even on the sides of freeways. Looks good on waterways.

Coniferous trees with needles falling for the winter

With the word "coniferous" we have the idea of ​​\u200b\u200bsuch trees that always remain green, like spruce or pine. Indeed, almost all conifers are evergreen. However, there are exceptions to this rule. What kind of conifers shed their needles for the winter? Ask this question to someone who is not too experienced in botany, and you will get the answer: "larch". This is correct, but only in part. Indeed, larch turns yellow in autumn, and then completely sheds its soft needles, that is, it behaves like our northern deciduous trees (hence its name).

But is this tree alone shedding needles for the winter? Are there any other conifers that behave in a similar way? A person unfamiliar with botany will not answer these questions. Meanwhile, among the conifers there are deciduous trees, and in addition to larch. Some of them can be seen in Batumi botanical garden.

Here is the first one. In winter, it is very similar in appearance to larch. However, a careful eye will notice that there is not a single cone on the tree. Under the tree, there are a lot of some kind of rhombic slightly thickened woody plates. Here you can also find winged seeds, reminiscent of pine and spruce seeds, only somewhat larger. It is easy to guess that rhombic plates are nothing more than scales of cones that have fallen from a tree. Consequently, the cones crumble when ripe, like a real cedar. And if so, then this is not a larch (her cones never crumble and hang “whole” on the branches for a long time). Before us is a completely different plant - the false Kaempfer larch (Pseudolarix kaempferi). The area of ​​​​its natural distribution is the mountains. East China. There she grows coniferous forests at an altitude of 900-1200 m above sea level. In culture, false larch is valued as decorative tree because of its beautiful needles.

The second deciduous coniferous tree is two-row taxodium, or swamp cypress (Taxodium distichum). His homeland is North America. The tree is named swamp cypress because it often grows in swamps. It is also called cypress not by chance: its spherical cones resemble the cones of a real cypress. But if the cones of an ordinary cypress are very strong and it is difficult to break them with a hand, then the swamp cypress has completely different cones. It is worth picking up a mature cone from the ground and squeezing it a little in your hand, as it crumbles into pieces.

Swamp cypress has a rare ability to develop special respiratory roots, the so-called pneumatophores. Unlike ordinary roots, they grow upward, rising above the ground. Appearance they are very peculiar - thick, woody processes of a bizarre shape, similar either to skittles or to some kind of knotty bottles. Respiratory roots are composed of very light, porous wood, although quite strong; a channel runs inside. They are vital for the plant importance. Through these processes, air penetrates to the root system of the tree, hidden in the marsh soil. And the soil of swamps is very unfavorable for plant life due to excess water and lack of oxygen. If there were no special pneumatophores, the tree could die. Respiratory roots grow from thick horizontal roots spreading from the trunk in different directions.

Thanks to the respiratory roots, the swamp cypress can grow in areas that are covered with water for several weeks or even months. Under these conditions, vertical roots grow to a height at which they are above the surface of the water. Their maximum height reaches 3 m.

In the Batumi Botanical Garden, well-pronounced respiratory roots can be seen in one of the large trees of the swamp cypress, growing in a very damp place (Fig. 20). Other specimens located in drier areas do not form such roots.

At the swamp cypress, the phenomenon of branching, already familiar to us, is observed - in the fall, whole branches fall along with the needles. True, this does not happen with all branches. Some of them remain on the tree, only needles fall off them.

Interesting geographical distribution swamp cypress. Currently, it grows wild only in the southeast. North America. But before it was widely distributed on the globe, including in Europe, where fossil remains of this plant are often found. The swamp cypress is one of the most valuable timber trees in North America and is heavily logged. Its wood is an excellent drill and ornamental material, it remains in the soil for a long time.

The foliage of the swamp cypress is beautiful, light green, lacy. This tree is often cultivated for decorative purposes on highly moist soils, along the banks of water bodies where other tree species cannot grow.

The third deciduous conifer is the famous metasequoia (Metasequoia glyptostroboides). It is a tree in the truest sense of the word "animated fossil": it is, as it were, "raised from the dead." It was met only in a fossil state and was considered completely extinct. And suddenly on the 8th of 1941-1942. in one of the regions of China, scientists accidentally discovered a living, rather old metasequoia tree. A little later, in 1944, a whole grove was found. It turned out that the plant was by no means extinct. This discovery made a real sensation in the botanical world. Similar cases also occur among zoologists when they find animals that were considered to have long disappeared from the face of the Earth (for example, coelacanth fish).

It is clear that in the Batumi Botanical Garden, as in other gardens, you can see only young specimens of metasequoia, they are no more than 20-30 years old.

What is a metasequoia? This is a slender tree with a straight trunk and a cone-shaped crown that starts almost from the ground itself. In summer, the tree is very decorative - the crown has a beautiful pale green color. The needles are soft, and the individual needles are almost the same as those of the swamp cypress.

In winter, the metasequoia does not attract attention to itself - only bare branches. You look at it from a distance - and you won’t even think that it is a coniferous tree species. Yes, you won't know right away. True, if you look at the ground, you can see that under the tree there are not leaves, but reddish dry needles. More precisely, whole branches with needles. Metasequoia, like swamp cypress, is a "branched" tree. IN winter time when there are no needles on the trees, the branches of both plants are quite similar. However, in metasequoia, thin young branches are arranged differently than in swamp cypress: they depart from thicker branches in pairs, one against the other.

Well-known and common representatives include the following.

Swamp (double-row taxodium)

The plant is native to North America. It is distinguished by strong wood and the presence of respiratory roots (pneumatophores). The development of the latter is due to the natural range of distribution of the species.

Found in swampy areas of the United States (from Texas to Delaware). Since marsh soil is different big amount moisture and lack of air, respiratory roots provide the plant with an additional source of oxygen. By autumn, not only leaves fall, but also twigs.

False Kempfmer

Outwardly very similar to Siberian Larch, it is easy for an inexperienced gardener to make a mistake. The difference lies in the fact that this species does not have cones that crumble when ripe into diamond-shaped plates, like in.

The plant's distribution area is the mountains of East China, where the plant forms forests. It has received distribution in landscape gardening culture due to the peculiar beauty of the needles.

metasequoia

The tall tree is distinguished by a straight trunk and a wide conical crown of light green color. The needles of the plant are soft, by autumn they turn yellow and fall, sometimes even along with the twigs.

The speed is different. growth and unpretentious care. unstable to temperature fluctuations, but it grows better in the area humid subtropics, along the outskirts of hollows and river beds.

Metasequoia and Taxodium are related species, despite being common to different continents. Each of the deciduous species has a number of features, but the seasonal shedding of needles unites them.

Siberian larch sheds needle leaves for the winter, what else is interesting about it

Siberian is distributed in Russia from the Sea of ​​Okhotsk to Lake Onega. It is considered the main species that forms the forests of this region.

Features of the species include:

  • Unlike other types of wood, over time, the durability of wood only increases, so it is often used in the construction of houses, shipbuilding. In museums, there are products made of larch, which have only darkened over the centuries that have been spent in the barrows of Altai.
  • A large number of Russian cities were built on this wood. In addition, it is known that even in tsarist times it was allowed for export. So the piles of houses in Venice were also made from this breed;
  • In addition to deciduousness, the plant is different, it can live from four hundred to five hundred years;
  • Larch belongs to dioecious plants, that is, both female and male cones are located on the same tree, which is typical for many coniferous species;
  • The plant perfectly tolerates not only a decrease, but also a significant increase in temperature. This feature makes it possible to grow it not only in the harsh conditions of the north, but also in the hot south. Drought, at proper care, will not harm the tree;
  • Tree trunks are straight, can reach a height of thirty to forty meters. But sometimes they can exceed this size up to fifty meters with a trunk thickness of up to two.

The mechanism of dropping foliage for the winter has developed in larch as a result of climate change. Seasonal cooling significantly impairs the process of enriching the plant with water, and in the presence of green foliage, this deficiency is greatly aggravated.

To avoid the danger of dying due to lack of water and oxygen, larch had to adapt.

Being an unpretentious and hardy species, larch has spread widely in many regions and regions. the globe. It is used both as a horticultural and industrial crop. A tree can not only decorate the site, but also ensure the longevity of the building.

Does fir drop needles for the winter

There are several types of deciduous conifers. Falling leaves in these species arose as a result of adaptation to a cooling climate. However, for most conifers, the preservation of a cheerful green appearance at all times of the year remains characteristic.

One of prominent representatives evergreen plant is considered to belong to the Pine family.

The main features of the species include:

  • Unlike other representatives of evergreen trees, fir reproduces not only by seeds, but also by layering, which are formed as a result of the grounding of its lower branches;
  • Monoecious - the trees are dioecious, both male and female genital organs are simultaneously formed on the same plant;
  • It tolerates shade well, the lack of good lighting does not depress the plant;
  • Growth in the first ten years of life is slow and only after that begins to accelerate sharply;
  • Average duration the life of a tree is from three hundred to five hundred years, sometimes it can live up to seven hundred;
  • Flowering begins at the age of sixty when grown in the forest and at the fortieth in the park;
  • Fir cones, unlike pine and spruce, are arranged vertically, resembling candles. They do not fall off, maintaining their integrity, but crumble on a branch, like in cedar and false larch in autumn or early winter.

Since fir belongs to evergreen trees. Unlike larch, this species does not completely shed its needles for the winter.

The renewal of the needles occurs gradually, regardless of the time of year. That is why it seems that the fir does not drop foliage at all.

The common belief that all conifers are evergreen is erroneous.

A striking example of deciduous representatives is considered to be larch - a tree unique in its durability, widespread in horticulture. Used for landscaping different sizes, wood is highly valued in construction.

You will learn more about larch and the secrets of its cultivation when watching the video: