Quercus

The genus Oak (Quercus) includes about 450 deciduous or evergreen trees, less often shrubs. Crown - from thick branches of a pyramidal, tent-shaped, weeping or spreading shape. In old trees, the trunk is covered with dark gray bark in cracks. The leaves of deciduous species are large, lobed or lobed-toothed; evergreen - small whole-edged, sawn or toothed. In autumn, they are very brightly colored (in red, orange or yellow tones). Flowers - male and female-on the same plant. Female-nondescript greenish color; men are collected in yellow earrings that appear on the face. early spring. Single-seeded dry fruits (acorns) in a shiny brown skin are partially covered with smooth or prickly lignified pluska. Common oak, or petiolate (Quercus robur), is a winter-hardy and drought-resistant plant of large size with rather slow growth. The columnar pointed oak is also very widespread (Q. robur var. fastigiata). The rock oak, or winter oak (Q. petraea), is very similar to the common oak, from which it differs only in smaller sizes and greater resistance to cold winters, but it is more sensitive to late frosts. Less common species: downy oak (Q. pubescens) grows up to 15 m in height, Turkish oak (Q. cerris) - a lush species with an egg - shaped crown, holly oak (Q. ilex)-with a rounded crown, cork oak (Q. suber), farnetto oak (Q. farnetto), coccifera oak (Q. coccifera), red oak (Q. rubra), marsh oak (Q. palustris), bright red oak (Q. coccinea), white oak (Q. alba).

The genus Oak (Quercus) includes about 450 deciduous or evergreen trees, less often shrubs. Crown - from thick branches of a pyramidal, tent-shaped, weeping or spreading shape. In old trees, the trunk is covered with dark gray bark in cracks. The leaves of deciduous species are large, lobed or lobed-toothed; evergreen - small whole-edged, sawn or toothed. In autumn, they are very brightly colored (in red, orange or yellow tones). Flowers - male and female-on the same plant. Female-nondescript greenish color; men are collected in yellow earrings that appear on the face. early spring. Single-seeded dry fruits (acorns) in a shiny brown skin are partially covered with smooth or prickly lignified pluska.

Common oak, or petiolate (Quercus robur), is a winter-hardy and drought-resistant plant of large size with rather slow growth. The columnar pointed oak is also very widespread (Q. robur var. fastigiata).

The rock oak, or winter oak (Q. petraea), is very similar to the common oak, from which it differs only in smaller sizes and greater resistance to cold winters, but it is more sensitive to late frosts.

Less common species: downy oak (Q. pubescens) grows up to 15 m in height, Turkish oak (Q. cerris) - a lush species with an egg - shaped crown, holly oak (Q. ilex)-with a rounded crown, cork oak (Q. suber), farnetto oak (Q. farnetto), coccifera oak (Q. coccifera), red oak (Q. rubra), marsh oak (Q. palustris), bright red oak (Q. coccinea), white oak (Q. alba).

Cultivation

Oaks are grown mainly in large parks and gardens on any sufficiently fertile soil. And only the red oak (Q. rubra) is an exception: it does not like calcareous, or alkaline, soils. However, it is desirable that the fertile soil layer is very deep - the fact is that the length of the roots in length can be 3 or more times the size of the crown. Depending on the climate, planting in a permanent place is carried out either in autumn or in spring: in the northern regions, preferably in autumn, in the southern regions - in spring. The distance between plants must be observed, which is determined by It is a type of crop, but in any case, you should leave more space for the development of the plant. An exception is hedges made of holly oak. In this case, intervals of approximately 1 m are maintained between the plants. This contributes to better rooting of young trees.

Oaks are grown mainly in large parks and gardens on any sufficiently fertile soil. And only the red oak (Q. rubra) is an exception: it does not like calcareous, or alkaline, soils. However, it is desirable that the fertile soil layer is very deep - the fact is that the length of the roots in length can be 3 or more times the size of the crown. Depending on the climate, planting in a permanent place is carried out either in autumn or in spring: in the northern regions, preferably in autumn, in the southern regions - in spring. The distance between plants must be observed, which is determined by It is a type of crop, but in any case, you should leave more space for the development of the plant.

An exception is hedges made of holly oak. In this case, intervals of approximately 1 m are maintained between the plants. This contributes to better rooting of young trees.

Location

Most oaks prefer a sunny place, but many species, such as holly oak, tolerate partial shade.

Temperature

Oaks can withstand sub-zero temperatures. And only the holly oak requires a milder climate and higher temperature conditions compared to other species.

Watering

It is necessary only for young plants, especially immediately after planting. Mature trees are always very resistant to periods of drought, even long ones.

Reproduction

Oaks are propagated mainly by seeds, which are collected in the fall. Acorns can be used for 2 months, so they are sown as quickly as possible - in pots or boxes, leaving in the open air. Oak seedlings do not tolerate high soil acidity, salinity, and waterlogging. Before moving plants to a permanent location, you should allow them to grow stronger for 2-3 years. Seedlings are planted in the open ground in autumn.

Diseases

In general, oaks are very resistant to diseases and pests - both of them can cause serious damage if the plant is not strong or, conversely, very old. Larvae of Thaumatopoea processionea, called "furry cats" in Europe, can cause significant foliage loss. Nests of these pests (carefully, you should work with gloves because of their very burning hairs!) with clusters of insects collected by hand and burned. Among other insects, small hymenoptera, especially nutcrackers, provoke the formation of growths (galls) on leaves and branches, but usually they do not cause serious harm. Aphids and oak phylloxera (Phylloxera quercus) cause the formation of necrosis and spots on the leaves. Some beetles, such as oak barbels and deer beetles, as well as the larvae of the odorous woodworm (Cossus cossus) make maze-like passages in the wood, although usually pests affect the plant that is already weakened for some reason. Especially dangerous are wood - destroying tinder fungi (Fomes, Ganoderma and Polyporus), which penetrate deep into the wood through surface damage to the plant, where they provoke the formation of smut. On trunks often you can notice the "polochkovidnoe" fruit body of these mushrooms. It is very difficult to get rid of them, and the most correct way is to remove the affected plant. The same should be done with plants whose roots are covered with rot, usually caused by honeydew (Armillaria mellea). Less acute is the problem with powdery mildew of oak (Micosphera alphitoides): it is manifested in the formation of whitish spots on the shoots and the upper side of the leaves. In this case, the plants are treated with sulfur preparations, caratan or anti-oidium preparations, but it is recommended to use protective equipment primarily on young plants.

In general, oaks are very resistant to diseases and pests - both of them can cause serious damage if the plant is not strong or, conversely, very old. Larvae of Thaumatopoea processionea, called "furry cats" in Europe, can cause significant foliage loss. Nests of these pests (carefully, you should work with gloves because of their very burning hairs!) with clusters of insects collected by hand and burned. Among other insects, small hymenoptera, especially nutcrackers, provoke the formation of growths (galls) on leaves and branches, but usually they do not cause serious harm. Aphids and oak phylloxera (Phylloxera quercus) cause the formation of necrosis and spots on the leaves. Some beetles, such as oak barbels and deer beetles, as well as the larvae of the odorous woodworm (Cossus cossus) make maze-like passages in the wood, although usually pests affect the plant that is already weakened for some reason. Especially dangerous are wood - destroying tinder fungi (Fomes, Ganoderma and Polyporus), which penetrate deep into the wood through surface damage to the plant, where they provoke the formation of smut. On trunks often you can notice the "polochkovidnoe" fruit body of these mushrooms. It is very difficult to get rid of them, and the most correct way is to remove the affected plant. The same should be done with plants whose roots are covered with rot, usually caused by honeydew (Armillaria mellea).

Less acute is the problem with powdery mildew of oak (Micosphera alphitoides): it is manifested in the formation of whitish spots on the shoots and the upper side of the leaves.

In this case, the plants are treated with sulfur preparations, caratan or anti-oidium preparations, but it is recommended to use protective equipment primarily on young plants.

Acquisition

On sale there are seedlings with an unprotected, open root system (cheaper) or with a lump of earth (more expensive, but easier to take root). Buy in the fall or early spring to immediately plant in a permanent place. It is necessary to choose not too overgrown copies.