The genus Oak belongs to the beech family and contains about 600 species. These include evergreen and deciduous trees. The Latin name for the family comes from the Greek language and means "rough."
Representatives of the oak family can be found in East Asia, North America even in a greater variety of species than in Europe. This is due to the fact that even during glaciation, the glacier attack was carried out from the north, and most plants "retreated" to the south. But the Alps became a natural barrier. In North America, plants that respond to frost have survived only in a southerly direction, but they still occur today.
Oaks are trees with a height of 20-30 m. Some species may also be taller - more than 50 m. But a small number of species are shrubs or very low shrubs that cover the ground with carpet, and their height rarely exceeds 2-3 meters.
Oaks are monoecious plants, their leaves and flowers appear at the same time - in May. Male flowers near the oak tree are collected in unusual inflorescences in the form of thin, long yellow-green hanging earrings, which are somewhat reminiscent of hazel earrings, hanging in large bunches of branches, almost no different in color from the young foliage that are located on the lower part of the shoots . Female, pistil flowers are small in size, located one at a time or, in some species, 2-3 at the top of the shoot. Subsequently, in September or early October, acorns appear from the female flowers.
Oak is one of the most magnificent and magnificent trees known for their solidity and durability. According to the ancient Roman scholar Pliny, centuries-old oaks were even recognized as a wonder of the world, whose age was compared with the age of the universe itself.
In Russia, in the middle lane, the most widely distributed is the oak oak - the most important forest-forming species in Western Europe and the European part of Russia. At low altitude, branches begin to depart from the trunk. Oaks love sunlight, and their branches are massive, twisted, have bizarre bends.
In North America rich in deciduous forests, there are many varieties of oaks, which, due to their unique decorative properties and unpretentiousness to adverse conditions, are widely used in landscaping.
The most common types of oaks
The natural habitat of red oak is eastern North America.
It is a tree 25 meters high, very fond of light, with dark green leathery leaves, in which the lobes are pointed. This species is considered very decorative, since in the fall the foliage acquires an orange and bright red color. In old trees, the leaves in the same period turn brown and yellow.
Acorns appear in the second year of a tree's life. They are wide, ovoid in shape, placed in a flat cup. Red oak loves light, especially the crown top lighting, but quietly tolerates side shading. Also indisputable properties of this plant are frost resistance, resistance to gases and poisons. This tree is a representative of those species that drown out city noise.
The second type - swamp oak - has a very slender, rounded crown, which becomes narrower with age. The average tree height is 25 m. There are no branches in the lower part of the trunk, it is branched evenly and fairly densely. The leaves of the tree are very beautiful, shiny on both sides, from below they are lighter, and from above - bright green. This species is not as hardy as red or leafy. In severe winter frosts, young shoots often freeze. In this case, acorns, although they are tied, do not ripen and fall.
In North America, the leaves are dark red in color, but in Moscow they turn yellow in autumn.
The white oak in the section of the leaf is similar to the swamp, but differs in a flatter rounded top. The height of the tree is 25 m, the branches are very wide and spreading, the crown is hipped. The bark of a tree is light gray, sometimes even white with cracks.
To the base, the leaves become narrow, deep, sometimes to the middle vein, they are separated by narrow notches. When the leaves bloom, they have a bright red hue, slightly pubescent and silvery, at a more mature age they acquire a bright green color, slightly bluish below. Autumn foliage is preserved on a tree. It is one of the most beautiful oak trees in North America.
Large-fruited oak is distributed in the Great Lakes region, often reaches 30 meters in height, and has a tent-like crown. The name of the tree is associated with large-sized acorns. In Moscow conditions, they do not mature every year and one at a time. It grows fast enough, hardy, but loves moisture.
The natural habitat of Mongolian oak is the southern part of the Far East, but now it is also found in Korea, China and Northern Japan. This is a very beautiful tree, reaching 30 meters. It forms vast forests on the slopes of mountains and along river banks. In autumn, the leaves of the tree acquire bright yellow-brown hues.
He loves sunlight, does not tolerate shading from above, but lateral shading, on the contrary, contributes to the rapid growth of a tree.
In Russia, there is notched oak, which also grows in China, Japan and Korea. Prefers mountain slopes and dry hills. Also photophilous, very resilient and fairly calmly tolerates drought. It gives a very good offspring during the year.
Oaks in landscaping
Oak is the basis of forest parks and large parks in areas where there are conditions suitable for its development. With a single landing, the tree becomes wide and short, with a spreading crown. In tight and group plantings, the oak grows taller, slender and straight. Decorative oak species are used in solitary sediments, looking especially good with conifers, while creating an elegant park landscape. Oak is often used for planting in the alleys, the distance between the trees should be about 6-8 meters. Oaks have a very wide and spreading crown, which requires a lot of space, and this should be taken into account when wanting to plant a tree on a personal plot.
How to propagate oak
Oak is undoubtedly the king among deciduous trees. And many landowners are not averse to planting this plant in their own place, in order to subsequently enjoy its majestic beauty. Oak is propagated in several ways, for example, by rooting green cuttings. It should only be taken into account that cuttings taken from adult plants almost never take root, but from young ones they are much more successful. According to the data, cuttings of annual plants take root at 70-90%, and biennial plants - 30-70%.
Also, rooting is influenced by the time of cuttings. For cuttings of young plants, the first decade of June is best suited, but for older plants, May.
As a good stimulant, you can use heteroauxin.
Oaks also reproduce well by planting fresh acorns. Harvested in September and October, for some species even November is suitable. Sow acorns should be immediately after assembly, not allowing them to dry out. If autumn is dry, then after sowing acorns they need to be watered and it is recommended to cover it with spruce branches to prevent damage by rodents.
If you do not have the opportunity to plant acorns immediately in the fall, then dry them up to 60% moisture retention. A dried, good acorn should not be dry, but the bun should not separate. Otherwise, acorns are overdried.
Dried acorns wound in the basement with excellent ventilation, the box with them should be closed in several layers: the first layer is sand 10 cm, the second is acorns 2 cm, the third is sand 2 cm. The humidity of the sand should be 60%, storage temperature - 2-5 degrees Celsius.
If the batch of acorns is small, then it can be left in the refrigerator, using a bag with small openings for breathing. The ideal temperature for storage will be 2-3 degrees. If you store acorns in a completely sealed bag, they will die. Every ten days it is advisable to take out the acorns and examine for mold. If it was found, rinse the acorn well, dry it and put it back in the refrigerator.
Storage for the winter can also be done by digging the acorns into the ground to a depth of 20 cm in autumn. They should be covered with a sheet of waterproof material, leaving a small layer between the acorns and the sheet, which will provide protection from rodents. Subsequent spring processing in spring is not necessary.
After proper winter storage after sowing in the spring, seedlings should appear in a month. During germination, the apex of the acorn cracks and a white root appears outside. After two weeks, it grows to 10 cm, and then throws the stem. In the first year of life, the seedlings of the tree reaches 10-15 cm.
How to plant an oak grove (video)
Proper tree pruning
Oak has monopodial branching, that is, its main stem continues to grow until the end of the plant's life, dominating the side shoots. All types of oak have a powerful straight trunk, occasionally - a few. It is possible to limit the crown by trimming the tree, which should be done once every 2-3 years. The aerial part of the tree is formed using various methods of pruning branches.
You can slow down the growth of the trunk by removing the apical kidney. You can also pinch the shoot, cut the branches, shorten the branches and shoots. The growth cut on the crown favors the branching of the plant. The best time for pruning oak is the end of winter and early spring. In winter, branches can be removed only if the temperature in the street does not drop below -5 degrees. Lower temperatures can cause freezing of adjacent sections of wood and bark. In summer, pruning a tree is also not recommended.
Sanitary pruning involves the removal of drying out, sick, damaged branches, as well as those that grow inside the crown.