We have already become accustomed to the elegant urban appearance of trees – a dark trunk on top and white underneath. But why do they whitewash the lower part of trees? Firstly, it is beautiful – after whitewashing, trees in the urban landscape really look elegant and harmonize with the white borders. However, this is not the only reason. In fact, paint or whitewash perform a protective function. And most often it is not even about pests, as many believe, although in some cases it protects from them too.
Whitewashing the lower part of the trunks performs not only a decorative function. Photo source: dzen.ru
Contents
- 1 In which countries are trees whitewashed
- 2 Why are they whitewashed trees in the city
- 3 Why are only the lower parts of the trees whitewashed
- 4 When to whitewash trees
- 5 What to paint trees with
In which countries do they whitewash trees
Many people believe that whitewashing trees is exclusively a legacy of the USSR. However, in fact, whitewashed trees are found in many other countries, such as Turkey, Belgium, Germany, Mexico, Greece, and even Florida in the USA.
Trees are whitewashed not only in Russia, but also in many other countries. Photo source: pikabu.ru
In the USSR, the tradition of whitewashing trees arose during the Great Patriotic War. According to an existing legend, the Soviet military needed to come up with something so that they could move unnoticed at night by ground transport. They couldn’t turn on the headlights so that the enemy wouldn’t notice. So someone suggested painting the curbs white, and where there weren’t any, the lower part of the tree trunks so that the columns of equipment could navigate by the light objects.
Why do they whitewash trees in the city
In the USSR and now in Russia, whitewashing trees has become a tradition. Most often, utility workers whitewash tree trunks before holidays, such as May, so that parks and streets look more well-groomed and elegant. Therefore, many housing and communal services workers who work in parks don’t even know the true purpose of whitewashing.
But, as has already been said above, whitewashing trees also has a practical meaning. The fact is that the bark is most often dark, almost black. As we know from school, the darker the color, the more it absorbs sunlight. For this reason, dark surfaces heat up more than light ones.
Whitewashing trees helps protect them from burns. Photo source: poryadok.ru
For plants, especially young ones, overheating is very dangerous, as it can cause burns. In addition, due to overheating, the tree bark can dry out and crack. It is much more difficult to cure a sick tree than to prevent the disease. Therefore, the lower part of the trunk is whitewashed so that it heats up less.
Why only the lower part of trees is whitewashed
It would seem that if the purpose of whitewashing is to protect the tree from overheating, then why only the lower part of the trunk is whitewashed? There is an explanation for this too. The whole point is that the trunk, that is, the section of the trunk between the root system and the lowest branch, is the most sensitive part of the tree.
If the tree is injured in the trunk area and is not treated in time, it may die. Therefore, whitewashing is aimed at protecting the trunk from overheating. The rest is more resistant to negative environmental impacts. But even if one of the branches is damaged and dries out, this will not lead to the death of the entire tree.
The lower part of the trunk is the most vulnerable part of the tree. Photo source: vitvesti.by
When to whitewash trees
We are used to trees being painted in the spring, most often, as already noted, housing and communal services workers do this before the holidays. However, from the point of view of trunk protection, this is not entirely true. Trees also need similar treatment in the winter and especially in early spring.
The fact is that the sun's rays heat the dark bark even in winter, and it heats up both under direct rays and those reflected from the snow. As a result, the bark thaws and heats up very quickly. At the same time, life processes are activated in the layers of living cells underneath it. However, when the sun disappears, the surface cools sharply, and the ambient temperature at this moment is often below zero degrees.
Sometimes sharp temperature fluctuations reach two tens of degrees, which leads to cell destruction. This disrupts the normal course of physiological processes in the tree. As a result, the bark cracks and “wounds” form on the trunk. Bacteria and fungal spores can penetrate through them, which ultimately leads to rot and can cause the death of the tree.
Experienced gardeners treat trees not in the spring, but in the fall. Photo source: woman.rambler.ru
Most often, young fruit trees such as apple trees, pear trees, cherry plums, cherries, apricots and plums suffer from sun rays in winter. Usually, the southern sides of the tree are affected. Therefore, experienced gardeners whitewash trees not in the spring, but in the fall, or do it twice a year – in the fall and in the spring.
It should be said that as trees mature, they become more resistant to sunburn, as the bark of the trunk becomes thicker. As practice has shown, some trees can withstand not only the sun's rays, but also an atomic bomb explosion.
What do they paint trees with
Often trees are simply whitewashed with chalk, for example, in city parks and squares. In this case, whitewashing only protects the tree from burns and performs a decorative function. However, as was said at the very beginning, treating the lower part of the trunk can also protect trees from pests. In this case, they use not chalk, but lime or special paint for trees that kills pests.
To protect trees from pests, use lime or special paint for trees
Before painting or whitewashing with lime, the trunk is cleared of bark scales and moss, under which insects often overwinter. But even if some insects remain under the bark, they die after applying the solution. In the spring, pests that overwinter in the soil will not be able to climb up the treated trunk.
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As a rule, only fruit trees are treated in this way. For non-fruit trees, the point of such treatment is questionable. Many insects that climb the trunk are not dangerous to the life of trees. In addition, they serve as food for birds, which already have a hard time finding food in the city.