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The deciduous shrub, known as the Japanese rhododendron, belongs to the extensive heather family. It includes about 1300 varieties, including indoor azalea.
Описание рододендрона японского
In the process of long-term selection, about 12 thousand varieties of Japanese rhododendron were bred. Most of the plants reach a height of 2 m. The duration of flowering is 2 months (May and June), while up to 1 flowers bloom on 400 bush. Bushes look very beautiful on which there is no foliage or it is just appearing, but at the same time the branches are strewn with flowers. Inflorescences of the Japanese rhododendron are formed from 10 or more corollas, most often having an orange-yellow hue. After the corollas wither, fruits are formed – boxes with very small (less than poppy seeds) seeds that ripen by October.
The life expectancy of the plant is high, the tallest varieties grow up to 100 years. There are varieties with erect stems and creeping. Mature shoots have a pronounced brown tint, and the most tender young and naked ones are green. The root system is fibrous, without hairs.
In the catalogs of planting material manufacturers, you can find many varieties and photos of Japanese rhododendron. The most common colors are orange, yellow, pink and white.
Сорта рододендрона японского
The classic orange Japanese rhododendron will brighten up any space, but the plant looks even more beautiful when surrounded by other shades. The following varieties are most popular with gardeners in central Our Country.
Japanese salmon rhododendron
In this variety, the calling card is not only a bright shade of lush and large inflorescences. The winter hardiness of the Japanese salmon rhododendron is its valuable quality, which made it possible to grow not only in the middle lane, but also in the front gardens of the Moscow region. It is easy to recognize the variety by key features:
- height – up to 2 m;
- flowers – salmon shade, up to 7 cm in diameter, collected in inflorescences of 6-12 pieces;
- flowering time – 3 weeks from mid or late May;
- foliage of an elongated green color, 10-12 cm long, acquires a fiery hue by September;
- gray bark.
For planting buy seedlings aged 2-4 years. The unpretentious Japanese salmon rhododendron is planted where the sun is not all day, otherwise the delicate flowers burn easily. Well suited places near the fences. The variety is very moisture-loving, but it requires top dressing every 2-3 years.
Japanese cream rhododendron
The cream shade of the petals in this group of varieties is often combined with a bright yellow flower core and the same large stamens. A pleasant delicate aroma is characteristic of all Japanese rhododendrons. The peculiarity is that it does not tolerate the neighborhood with large-sized ones, but it feels great on lawns surrounded by grass, on slopes. It is advantageous to plant it in areas with large elevation differences, so it is often used to create terraced landscape compositions.
Depending on the variety, the height of the bush reaches 1,2-2 m, and it grows in one place with proper care up to 40 years. The leaves grow up to 4-10 cm in length, and the flowers are collected in inflorescences of 6-12 pieces. The corollas are so lush that the foliage is almost invisible behind them. By autumn, the foliage on the bushes acquires a yellow-purple color instead of dark green.
Rhododendron Japanese Babushka
Refers to dwarf varieties. A compact bush grows only 50 cm in height and width. Semi-double carmine-pink flowers are very lush. Only the red Japanese rhododendron looks brighter. Glossy dark green foliage turns yellow in autumn. The variety is semi-evergreen.
Planting is recommended in semi-dark areas. Belongs to the 6th winter hardiness zone. Loves abundant watering and mulching. Pruning bushes require 1 time per year – late autumn or early spring before bud break.
Rhododendron Japanese Schneeperle
Azalea rhododendron Japanese Schneeperle belongs to the earliest varieties. Flowering begins in mid-April and lasts until the end of spring. Boiling white flowers look great in festive bouquets, such as wedding bouquets. Corollas of flowers are relatively small – 4-5 cm in diameter, but very lush, reminiscent of tiny roses.
The bush is unpretentious, but grows very slowly. A plant aged 10 years has a height of only 35 cm and a width of 55 cm. The main application is the formation of borders in multi-row decorative plantings. The peculiarity of the variety is that it needs formative pruning at the end of flowering in June. So the plant has an incentive to form flower buds for the next season. Withstands frosts down to -29 °C. The root system is shallow, prone to growth in breadth. It is highly not recommended to deepen the root neck, which can lead to the death of the bush.
Rhododendron Japanese Snow White Prince
This variety can also be found on sale under the name White Prince. Flowers are either completely white or with a pale pink core. It looks especially impressive next to the orange Japanese rhododendron / azalea. The bush is tall – up to 2 m in height. Flowers of medium size – 6-8 cm in diameter. The leaves are elongated green, up to 10 cm long. Winter hardiness is average, in regions with frosty winters, covering agricultural technology is recommended. Planting material – seedlings of 3 years of age. Younger seedlings obtained from seeds are grown in greenhouse conditions. For landing in open ground, choose a shaded place, well protected from strong winds and direct sunlight.
Winter hardiness of Japanese rhododendron
Not all varieties are equally good for regions with frosty winters. Whether a particular variety is suitable for a given area must be clarified in advance. Here is a list of the most winter-hardy varieties that can be grown even without sheltering bushes for the winter:
Name | Winter temperature limit, °C |
Grandmother | – 23. |
Golden Lights | – 42. |
English Roseum | – 34,4. |
Karens (Karens) | – 31. |
Mount Saint Helens | – 32. |
Nova Zembla (Nova Zembla) | – 32. |
PJM Elite (PJM Elite) | – 32. |
Rosy Lights | – 42. |
Roseum Elegans (Roseum Elegans) | – 32. |
White Lights | – 42. |
In its natural habitat, the Japanese rhododendron grows on mountain slopes at an altitude of up to 2000 m above sea level.
Planting and caring for Japanese rhododendron
It is quite possible, if desired, to grow a beautiful Japanese rhododendron from seeds. The case is interesting and will take more than one year. The fact is that young plants of the first year of life are extremely demanding for care, so the sowing is carried out in containers, where bushes are usually kept for up to 3 years. Only after that they are transferred to the flower beds or put up for sale. The older the bush, the higher it is valued. If the average price of a 3-year-old Japanese rhododendron ranges from 300 to 1000 rubles on average, then for a 7-year-old, the fair value is from 15 thousand rubles.
Long and slow vegetation is the main reason why varietal Japanese rhododendrons are sold in specialized stores as seedlings of different ages. It is enough to carefully deliver it to the site and land it on the chosen place in order to admire its lush spring flowering for many years to come. The growth of one year is small, low-growing varieties can increase by only a few centimeters in height per season.
Selection and preparation of the landing site
The vast majority of Japanese rhododendrons do not tolerate direct sunlight well. Shrubs are recommended to be planted where the sun appears only for some part of the day – morning or evening. It is optimal to plant bushes along fences or borders, as well as under the shelter of a facade or other bushes. In a completely open clearing, where a bush cannot hide in the shade for a second, its flowers and leaves will be seriously tested. The risk of death due to burns is very high.
The soil in the places where the plant comes from is least of all similar to black soil. In fact, this is a complex substrate in which all kinds of plant remains abound: branches, needles, foliage. Fertile soil is prepared for planting bushes, mixing it abundantly with mulch and adding clean river sand for additional friability. On clay and heavy soil, the Japanese rhododendron will wither. Excellent additives – peat and rotted needles. The acidity of the substrate should be high, Japanese rhododendrons do not like neutral or alkaline soils.
Seedling preparation
Since the planting material comes from nurseries where the bushes were kept in greenhouse conditions, they need to acclimatize before planting in open ground. To do this, the tub with the plant is hardened. At first, for half an hour, and then gradually increasing the time interval, it is taken out into the fresh air at the warmest time of the day, leaving it in partial shade. After 7-10 days, you can start planting in a pre-prepared pit.
Rules for planting Japanese rhododendron
The root system of the bush does not exceed 1 m in height in an adult plant. A planting hole is dug to a depth of up to 50 cm. Vermiculite or cheaper expanded clay, fine gravel for optimal drainage must be poured into its bottom.
The excavated soil is thoroughly mixed with needles, peat, mulch, a little complex mineral fertilizer is added. A cloudy but warm day is chosen for planting. After placing the roots in the pit, they are covered with the prepared substrate and watered abundantly. A funnel is formed around the trunk of the bush so that when watering, the water does not spread past. From above, the earth must be sprinkled with mulch. It is impossible to deepen the root neck, it should be flush with the ground level.
Watering and top dressing
Japanese rhododendron does not tolerate drought well. If the site has a natural or artificial reservoir, then the bushes can be planted along its banks. In other cases, throughout the warm season, the Japanese rhododendron needs regular abundant watering. Mulching the planting with needles or dry foliage will help prevent critical drying of the soil under the bushes.
Feeding the Japanese rhododendron is almost not required. Once a season, a sodium-potassium-phosphorus combined mixture is applied at the rate of 5-10 g/m2. The rest of the plant receives from decaying plant residues. Several times during the summer, needles, peat, heather land are poured under the trunk.
Trimming
The picture shows what a Japanese rhododendron looks like after pruning (2). They run it several times. There are types of cuts:
- sanitary – in early spring, broken and frozen branches are removed from the bushes;
- formative – before flowering, they get rid of bare shoots without branches to get a symmetrical neat crown;
- rejuvenating – after flowering, it is performed to stimulate growth if necessary, it provides for shortening the shoots by 20 cm.
Preparation for winter
Rhododendrons in Japan, growing on gentle mountain slopes, tolerate snowy winters well and do not need any care. In Our Country, it is better to take care of the bushes in advance, increasing the chances of the Japanese rhododendron to winter safely.
First of all, pruning is carried out, removing branches affected by diseases and pests. If the bush is old enough, then you can shorten the shoots by 20-30 cm to stimulate the active growth of dormant buds. Winter-hardy varieties do not need shelters, but semi-evergreens will need shelter. For this, agrofibre is used. The covering material has good air permeability, but does not allow the branches of the bushes to freeze in dry winters with little snow.
Another important event after the fall of the foliage of the Japanese rhododendron is watering and top dressing. Up to 10 liters of water are poured under each bush, dissolving 8 g of superphosphate and 6 g of potassium sulfate in it.
Reproduction
Japanese rhododendron lends itself perfectly to propagation by cuttings, layering, dividing old bushes. Rare hybrids are grafted onto the trunks of winter-hardy varieties. If you want to get an exact copy of your favorite Japanese rhododendron, you should cut a stalk from 15 cm long in the spring. The lower 2-3 leaves are removed. A branch of Japanese rhododendron is placed in moist soil and rooting is expected within 2-3 months. If by August the root system of the bush has formed of sufficient size, then it is possible to land in open ground, otherwise it is postponed until next year. In winter, containers with cuttings are left in a lighted room at a temperature of + 8-12 ° C.
Diseases and pests
With insufficient aeration of the root system, Japanese rhododendrons suffer from numerous fungal diseases. For prevention, bushes are recommended to be regularly treated with a solution of Bordeaux liquid.
If the soil is not acidic enough, then Japanese rhododendrons can suffer from root rot. This can only be corrected by increasing the acidity of the soil, for example, sprinkling the soil with coniferous litter and peat. Solutions of colloidal sulfur, ammonium nitrate, potassium sulfate also help.
Numerous garden pests, common in central Our Country, affect cultivated and wild varieties of Japanese rhododendron. Insecticides showed good efficiency: Iskra, Aktellik, Fitoverm, Aktara.
Conclusion
Japanese rhododendron is a very beautiful and non-capricious plant. The right place for planting, the soil prepared in advance and regular watering are the main conditions for active growth and abundant flowering. White, yellow, pink, red inflorescences will be the best decoration of any garden in spring, and lush foliage in summer and autumn.
Japanese salmon rhododendron reviews
