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The Korean or Manchurian cedar grows in Primorye, the Amur Region and the Khabarovsk Territory. Outside of Our Country, it is distributed in the northeast of China, in central Japan and Korea. Due to valuable wood, the culture is almost completely exterminated in China, and for the Amur Region it is protected and listed in the Red Book.
How to distinguish a cedar pine from a cedar
In fact, the Korean cedar is not a cedar at all. It doesn’t even belong to the genus Cedrus. Its full botanical name is Korean Cedar Pine (Pinus koraiensis), and it belongs to the numerous and diverse genus Pine. Such confusion in the language arose a long time ago, and it seems that no one is particularly embarrassed.
Korean cedar nuts (which, by the way, are not nuts in the botanical sense), unlike real seeds, are edible and are a valuable food and medicinal product. Cedrus and Pinus, although they belong to the same family – Pine, but have a lot of differences:
- Korean cedar grows in a temperate and cold climate, while the real one is very thermophilic;
- the roots of pines go deep into the earth, while cedars spread them in breadth and can be uprooted by a strong wind;
- the needles of the Korean cedar are long, can reach 20 cm, while the real needles grow up to a maximum of 5 cm;
- the needles of a real cedar are collected in bunches of 40 pieces, of a Korean one – 5 each;
- the cones of these cultures are very different from each other;
- the seeds of the cedar pine are edible, covered with a hard peel, which is why they really look like nuts, while those of the cedar are much smaller, with a thin shell, and are also equipped with a large wing.
There are other differences, but to know the culture, just look at the needles or the cone.
There are four types of cedar pines:
- Korean;
- Siberian;
- European;
- Stlanikovaya.
All of them have edible nuts and are only distantly related to real cedar.
True cedar (Cedrus), in turn, includes three types:
- Atlas;
- Lebanese;
- Himalayan.
Korean pine:
Lebanese cedar:
Description of Korean cedar
Korean cedar pine is an evergreen coniferous tree up to 40 m high with a multi-peaked, low-drooping crown in the shape of a wide cone. The ends of the outstretched branches are raised, the bark is thick, smooth, dark gray or gray-brown. Young shoots are brown, with a reddish edge.
The average length of bluish-green hard needles with blunt ends is 7-15 cm, the maximum is 20 cm. Triangular needles are collected together in 5 pieces and live 2-4 years.
In May, yellow or pale pink male microstrobili located inside the crown bloom on the Korean cedar. On the tops of large branches, female cones are formed. During flowering, they are beige or pale pink, after fertilization they turn green, at the end of summer they become light brown and remain so until next spring. At the beginning of the second growing season, the cones begin to grow actively and turn green again. After maturation, they are painted in beige or light brown color.
The size of ripe cones of Korean cedar pine is up to 18 cm long (some up to 23 cm), diameter is about 6-9 cm. The shape resembles an elongated egg with scales bent outwards. The seeds, incorrectly called pine nuts, are up to 1,8 cm long with a maximum diameter of 1 cm.
Cones ripen in autumn, one and a half years after pollination. Some of them fall off, some remain hanging until spring. Fruiting begins at 25-30 years old, the life span of Korean cedar is up to 600 years.
Differences between Siberian and Korean cedar pine cones
Various sources pay regrettably little attention to the description of the cones of various cedar pines. In Our Country, three species are widespread – Korean, Siberian and Stlanikova. And although they are very different from each other, lovers can easily recognize only the last species – the dwarf cedar. It is a small tree or shrub that bends its branches to the ground and forms impenetrable thickets.
The other two pines are not only confused, but also often inserted into articles about the Korean cedar, photographs and descriptions of the Siberian cedar. We need to distinguish them:
- Mature cones of Korean pine are twice as large as those of Siberian pine.
- Korean cedar seeds reach a length of 18 mm, Siberian – a maximum of 12 mm.
- During flowering, the cones of the Korean cedar are beige, during the ripening period they are green. The Siberian has crimson and purple, respectively.
- Cones of Korean cedar ripen in October, Siberian – by August.
The difference between cones and seeds is easy to see in the photo of Korean cedar, Siberian cedar and dwarf pine.
Varieties of Korean cedar pine
Cedar pines look attractive, but they are too big for small areas. Therefore, breeding is aimed not so much at breeding varieties with an original crown shape or bright needles, but at reducing the size of the tree.
Cedar Korean Sulange
This is not a variety, but a variety of Korean cedar pine. A tree up to 40 m tall with long (up to 20 cm) bluish-green needles begins to bear fruit in the 15-20th year of life. The crown is dense, openwork. Sulange tolerates air pollution much better than the main species, which allows it to be grown in city parks. Of great economic importance is fruiting, which begins 10 years earlier than that of ordinary Korean cedar.
Pine Korean Silverey
Silveray is an ornamental variety with a pyramidal crown and long, slightly twisted needles that have a silvery blue tint. By the age of ten, the tree reaches a height of 250 cm, with a diameter of 120 cm, increasing annually by 25 cm.
The variety is highly frost-resistant, demanding on soil fertility and does not tolerate stagnant water at the roots.
Korean Cedar Morris Blue
This variety is bred in Pennsylvania and has a high frost resistance. Forms a dense conical crown with silver-blue needles collected in 5 pieces. During the season, the growth is 15-20 cm. The adult Korean cedar Maurice Blue grows up to 3,5 m with a crown width of 1,8 m.
The bark is gray, especially attractive in winter. It tolerates urban conditions poorly, requires a sunny location, does not tolerate stagnant water in the root area, but tolerates drought well. Lives up to 120 years.
Korean cedars of selection
In the post-Soviet space, the Tomsk enterprise OOO Siberian Academy of Trees and Shrubs has been breeding Korean cedars for more than 20 years. They created the Blue Amur variety, which is distinguished by blue needles and a height of 4 m.
In the Far East, the breeder Alexander Simonenko is engaged in Korean cedar pine. In the Tomsk nursery, two dwarf early fruitful varieties are currently being tested: Patriarch and Svyatoslav.
Unfortunately, it is almost impossible to buy cultivars – they are bought up on the spot, preventing them from reaching even two years of age.
Growing Korean cedar from seeds
Before planting Korean cedar seeds, it should be noted that varieties are propagated only by grafting. Species tall plants will grow from their nuts, unsuitable for decorating a small area. For planting Korean cedars in order to obtain a crop, the seeds of plus, that is, the best, trees are better suited. To do this, choose the largest cones with large scales.
Sowing seeds in autumn
From the end of September to the beginning of November, Korean pine seeds are sown without stratification. Germination will be 91%, while during spring planting it will be 76%. Pre-seeds are soaked for 3-4 days in a 0,5% solution of potassium permanganate and sown on ridges in rows spaced 10-15 cm apart.
They are closed to a depth of 3-4 cm and first mulched, and then covered with spruce branches. This will not only protect the soaked seeds from freezing in winter, but also save them from mice and birds. The sowing rate is 200 pieces per linear meter – the seedlings of the cedar pine are not afraid of thickening.
spring sowing
When sowing seeds of Korean pine in cedar spring, it is imperative to carry out stratification. Ideally, this takes 80-90 days. Seeds are soaked for 3-4 days in a solution of citric acid and heteroauxin, placed in a box with wet sawdust or sand and left outside under the snow.
But what if the planting material is purchased in the spring? Soak the seeds in warm water for 6-8 days, changing it every 2 days. Then mixed with washed sand and left at room temperature. Korean cedar seeds will hatch in about a month or a little more.
They are immediately put in the refrigerator or transferred to a room with a temperature close to 0 ° C, where they are stored until planting in the ground.
Seeds that have been treated with low temperatures are sown on ridges in late April or early May, just like in autumn.
Further care of seedlings
In the spring, in order to prevent the birds from pecking at the seedlings, the ridges are covered with a transparent film, it is removed only after the shell has fallen off. The picking of cedar pines is carried out very early, in the cotyledon state, and even better before they open. Then the survival rate will be about 95%.
Before planting in a permanent place, seedlings are transplanted into shkolki several times. It is best to carry out the operation in the spring, but if necessary, it can also be done in the fall. First, three-year-old cedar pines are planted at a distance of 30-35 cm in rows 1 m apart from each other. After 3-5 years, they are transferred to a new school and arranged according to the 1×1 m scheme.
All this time, cedars are moderately watered, fed and protected from the midday sun. Coniferous bedding is added to the soil of the shkolok – this makes the seedlings grow faster.
Landing in open ground and care
When planting Korean cedar, there should not be any particular difficulties. It is important to choose a quality seedling and a place for it – adult pines do not tolerate movement well. To get a good harvest, at least two trees should grow nearby.
Selection and preparation of the landing site
Korean cedar prefers acidic, moderately fertile soils rich in humus and permeable to water and air. They grow well in stony soils, are resistant to high winds and tolerate shading at a young age. Over time, pines become very photophilous.
Korean cedars can grow in areas with groundwater more than 1,5 m – their root system is powerful, deep into the ground, and does not tolerate soaking. When preparing the site, the roots of weeds are removed from the soil, stones, if any, are left.
The landing pit should be spacious enough – about 1-1,5 m deep and in diameter. To prepare the nutrient mixture, the top layer of soil is mixed with 3-5 buckets of leaf humus, acid peat and at least 20 liters of coniferous litter.
All these additives acidify the soil and make it loose, permeable to air and water. With close groundwater standing, the pit is made deeper and drainage is poured onto the bottom – gravel, broken red brick.
Preparation of planting material
It is best to immediately plant large-sized Korean cedar pine – ten-year-old trees above 80 cm. But they are quite expensive, and at least two copies are needed to get a crop. Therefore, many gardeners are forced to buy small seedlings. Their only advantage over large-sized ones (except for the price) is the ease of landing.
Container plants are watered the day before moving outdoors. Dug seedlings should be bought with a large earthen clod, protected by damp burlap or film. It is recommended to plant them as soon as possible.
Rules of landing
Korean cedar pines planted for ornamental purposes can be spaced 4 m apart. To ensure good fruiting, the minimum distance between trees is 6-8 m. If space permits, it is better to increase the distance to 10-12 m.
Before planting the Korean cedar pine, the planting pit dug in advance is completely filled with water, previously covered with 1/3 of the fertile mixture. When moisture is absorbed:
- Fertile soil is added to the bottom so that the root neck is flush with the edge of the pit.
- A Korean cedar is installed in the center.
- The planting hole is gradually filled with a fertile mixture and rammed.
- Check and, if necessary, correct the position of the root neck.
- Korean cedar is watered abundantly.
- The trunk circle is mulched with sour peat or coniferous litter.
Watering and top dressing
Great importance is attached to feeding and watering the cedar pine in the first 10 years of its life. Then fertilizers are replaced with mulching, and watering is carried out several times during the summer if the weather is dry.
For a young plant care should be thorough. For top dressing, it is best to use special fertilizers for conifers. They are released for each season separately, keeping the balance of substances necessary for the tree, and are used 3 times during the growing season. If it is not possible to use special top dressing, give the usual:
- in spring, after the snow melts – with a predominance of nitrogen;
- at the beginning of summer – a complete mineral complex;
- in the middle or end of August – phosphorus-potassium (without nitrogen).
Throughout the growing season, Korean cedar, like other coniferous crops, is useful to give foliar top dressing. For this, it is better to use chelate complexes and magnesium sulfate.
Watering young cedar pines is carried out as the soil dries out. It is better to skip watering than to allow water to stagnate in the root area.
Pruning and shaping Korean cedar
Pruning is not included in the care package for Korean cedar. In early spring or autumn, only dry branches are removed. Formative pruning is not carried out at all.
Preparation for winter
Korean cedars are covered for the winter only in the first year after planting. It is a winter-hardy crop that tolerates temperature drops well. Seedlings are wrapped with white agrofibre or spandbond and secured with twine.
The yield of Korean cedar
Seed-grown Korean pine pines begin to bear fruit 25-30 years after germination, grafted – sometimes after a few years. Under natural conditions, trees often give a harvest only after 60 years.
Cones ripen at the end of October, the next year after pollination. Each contains from 100 to 160 seeds weighing 0,5-0,6 g, and the core is 35-40% of the weight of the “nut”.
The cones of the Korean cedar pine grow in groups, and only on the tops of the trees, only a few can be located on the branches adjacent to the crown. On young specimens, the seeds are usually larger than on old ones.
Under favorable conditions, Korean cedar reaches its maximum fruiting by 100-170 years. It continues up to 350-450 years. Good crops are harvested every 3-4 years, but the complete absence of fruits is almost never observed. In a good year, one adult tree produces up to 500 cones, that is, 25-40 kg of “nuts”. Under natural conditions, the yield can range from 150 to 450 kg/ha.
The productivity of the cedar forest depends on the age of the trees and the location. The largest yields are produced by Korean pines, adjacent to hazel, maple, oak and linden, growing on the southern side of the lower part of the mountains.
Diseases and pests
Korean cedar, like all pines, is often affected by pests and gets sick. The most dangerous age for species plants is 30-40 years. Varieties require constant attention. Artificial plantations of cedar pine suffer from gas pollution and chlorosis.
The most dangerous disease is resin cancer, which is also called seryanka or blister rust.
Of the pests of Korean cedar pine, it is worth highlighting:
- pine shield;
- pine moth;
- hermes – pine aphid;
- pine owl;
- shoot pine silkworm.
When attacked by pests, trees are treated with insecticides, diseases are treated with fungicides. On large plantations, the processing of pine cedars is difficult.
Reviews about Korean cedar
Conclusion
The Korean cedar is a beautiful large tree, slow growing, long-lived and producing delicious, healthy seeds. Species plants are used in park culture; owners of small plots can plant varieties. For a tree, you need to choose the right place and surround it with minimal care in the first 10 years of life, then it practically does not cause trouble for the owners.