Actual topic

Cedar: problems of transplanting large trees, diseases and pests

Author: Shcherbakov A.N., PhD, Researcher, Department of Ecology and Forest Protection, Moscow State University Forests
Siberian cedar

Siberian cedar

The development of cottage construction in Russia has caused a wave of interest in various conifers, which are distinguished not only by a wide variety of forms, but also by high decorativeness. Among them Siberian cedar,or Siberian cedar pine(Pinus sibirica, which can be safely attributed to exclusive plants, not only because of the rarity, but also by purely external data.

The overgrown cedar is a powerful tree, up to 30 - 35 m high, with a life expectancy of up to 900 years. Young cedars, which have grown freely, with a wide-pyramidal, almost rounded crown, look especially decorative. It is not surprising that many legends are associated with the cedar, rooted in the distant past. And not only legends, but also the traditions of planting cedars in estates, monasteries and memorial sites ... Not so far from Moscow there is a monastery where cedar is growing, which is more than 500 years old.

In the Moscow region and nearby regions, you can find cedar pine about 30 years old, but the decorative value of such trees is low because of the dense planting, not thinned out in time. The external data of these cedars are far from perfect - one-sided trees, elongated from a lack of light, are usually not in demand. Really beautiful cedar pines grown in freedom are extremely difficult to find.

It is difficult not only to find, but also to transplant such a tree due to its size. Transplanting large cedars is usually carried out in winter, when it is possible to take a plant with a large clod of soil and retain most of the roots. A large lump with roots, a successful planting, the use of rooting stimulants is not yet one hundred percent of successful survival. When transplanting such a large plant, part of the roots that go beyond the boundaries of the selected coma are inevitably chopped off. This means that a mismatch between the root part of the tree and the crown will inevitably arise - through the leaves (needles) it will evaporate more water than the root system truncated during transplantation can absorb from the soil. During this period, the plant is inevitably weakened and stressed, especially if the spring is dry and hot. In a state of stress, plants secrete special substances, by the smell of which they are found by stem pests (bark beetles, golden beetles and others).

Cedar tree affected by bark beetles

Cedar tree affected by bark beetles

The main danger for the transplanted cedars is represented by bark beetles, among which ordinary engraver(Pityogenes chalcogrphus) occurs most often. After the establishment of positive daytime temperatures and snow melting, bark beetles come out after wintering. The years of an ordinary engraver are most often observed in the first ten days of May. As mentioned above, beetles find a weakened tree by smell. The males fly out first and gnaw out passages under the bark. In them, females lay eggs and larvae develop in the same place under the bark. As a result, tissue necrosis is formed on the surface of the trunk on an area of ​​about 10 - 15 square meters. see During the summer tens of hundreds and even thousands of beetles attack the tree. As a result, a tree that died by the end of summer. Protection against bark beetles is very difficult and can only be done by a plant protection specialist. If you skip the beginning of the colonization of the tree with stem pests and do not protect it, then at the stage when the beetles have gone under the bark, and even more so, when the larvae have already appeared, the fight against these pests is practically ineffectual. At the first stage of the settlement of bark beetles, the tree itself defends itself from pests - it floods their passages with resin. Sometimes successfully, and the tree survives without special protection measures, but often the plants die. The first sign of populating a tree with bark beetles is the appearance of small holes on the bark of the trunk and large branches through which droplets of resin are released.

Hermes on the cedar

Hermes on the cedar

Another problem not only for transplanted cedars, but also for those growing in plantings, is an insect - a pest of young shoots and needles - siberian hermes(Pineus sibiricus). Like aphids, hermes proboscis pierces the covers of young shoots and sucks out the juice. They look like small white pieces of fluff scattered over the needles and bark. This impression is created due to the hairy outgrowths on the surface of the integument of the body. It is this “fluff” that creates the main difficulties in the fight against Hermes. When plants are treated with preparations from pests, aerosol droplets do not reach insects, but are retained by this "fluff" and as a result, the pests do not die. Only insecticides acting through plant sap can be used. Not only the Hermes themselves, but also the eggs laid by the females, are protected by the same “fluff”. One clutch can contain up to a hundred eggs, and there are thousands of clutches on the cedar. It is not surprising that after such an invasion of pests, the needles are covered with yellow dots - traces of punctures through which the juice was sucked out, and the damaged shoots are deformed or dry out. During the summer, there may be 2 - 3 generations of Hermes. By autumn, only large females can be found at the ends of the branches, which are preparing for wintering. They will spend the whole winter right there, in lumps of "fluff", in order to come out in the spring and repeat all over again. The fight against hermes is complicated by the fact that it is necessary to control not only the exit of females after wintering, but also the release of young pests, called "vagrants". Tramps are quite mobile and with their help this pest settles. In addition, at the vagrant stage, Hermes is most vulnerable to chemicals.

Cedar. Cancer

Cancer

Not only pests, but also diseases prevent the cedars from living. The most common of these is pine needles rust... Rust appears most often in warm and humid seasons. Orange-yellow bubbles appear on the needle. A little later, you can see a yellow powder on their surface - these are spores of rust fungi that infect leaf tissue. With severe damage to the needles, yellow-brown spots are formed on its surface - these are dead areas. Severely affected needles may fall off. Rust gets on cedars from coltsfoot, sow thistle and some other plants, on which it passes part of the development cycle. This disease does not bring much harm. Much more dangerous blister rust and shoot canceralso caused by parasitic fungi. These diseases are difficult to treat and only in the early stages, at which they may not have obvious external manifestations.

From all that has been said, the main points can be distinguished when caring for transplanted plants:

  • protection against stem pests (bark beetles, golden beetles, barbel, etc.) is necessary, especially in the first season after transplantation,
  • the use of anti-stress drugs and stimulants to facilitate rooting,
  • carrying out protective treatments from Hermes every season from the beginning of May to July,
  • preventive protection against fungal diseases is carried out during wet seasons.