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Rhododendrons are a fairly extensive genus of ornamental shrubs and semi-shrubs, including more than 600 species. Due to their unpretentious cultivation and excellent appearance, these plants are widely used to create flower arrangements, as a decoration of parks and squares, in ornamental gardening. Evergreen rhododendron is of particular interest to florists. It fully combines all the decorative qualities of this plant, and its resistance to negative temperatures makes it possible to grow it in many regions of the country.
Description of evergreen rhododendrons
Evergreen rhododendrons belong to the Heather family. This shrub may be known to many gardeners as azalea, but this is not entirely correct. Azaleas are a separate subspecies of rhododendrons, and there are also many evergreens among them.
A full description of evergreen rhododendrons is given in the table:
Parameter | Value |
Plant type | Evergreen perennial shrub |
Root system | Superficial |
Stem | Straight, from 0.5 to 4 m high, depending on the variety |
Leaves | Dark green, glossy, oval-lanceolate, with a dense leathery surface |
Flowers | They resemble bells in shape. Collected in cap-shaped inflorescences of 6-20 pcs. The colors can be very different: white, pink, purple, yellow, etc. |
Flowering period | May June |
Seeds | Collected in seed-boxes. Ripen in late August or early September |
Evergreen rhododendron varieties
Of the many species of rhododendrons, only a small part are deciduous shrubs. The rest of the foliage is not discarded for the winter, but only folded into a tube. Below are the most famous varieties of evergreen rhododendrons.
Katevbinsky... One of the most popular types. One of the tallest rhododendrons, reaching a height of 4 m. With good care, it can live up to 100 years.
Blooms in May-June. Delicate purple flowers are collected in large inflorescences of 10-20 pcs. The bush is dense, the diameter of the crown can reach 2 m. On the basis of this variety, a large number of frost-resistant hybrids of various colors have been bred.
English Roseum... One of the well-known hybrids derived from the Katevba rhododendron. It grows as a dense bush, the height and diameter of the crown of which can reach 2.5 m. Flowers have a characteristic mauve color with orange specks. Dome-shaped inflorescences usually contain 8-10 flowers. Below in the photo is a hybrid evergreen rhododendron English Roseum.
The variety is distinguished by good resistance to adverse weather conditions, it tolerates frost, rain and drought well. Blooms in May-June.
Karens ... The plant belongs to the Japanese azaleas. Forms a dense compact bush with a diameter and height of up to 1.5 m. Flowers are reddish-lilac, with dark specks.
A distinctive feature of the variety is the strong aroma of flowers. Japanese azalea Karens blooms in May-June.
Nova Zembla... Another hybrid of the Katevba rhododendron. The bushes are distinguished by their solid size - up to 2.5 m in height and up to 2.1 m in diameter. The flowers are reddish-pink, bright, with dark burgundy spots. Collected in dense spherical inflorescences, resembling peony flowers from afar.
The evergreen rhododendron Nova Zembla blooms in May. The plant tolerates drought and direct sunlight well.
Marcel Menard... The bush grows up to 1.5 m. The crown is dense, up to 1.2 m in diameter. It blooms with large (up to 9 cm) purple flowers in the form of a wide bell with a characteristic golden middle. The cap-shaped inflorescence can contain from 9 to 18 flowers.
Flowering begins in May, sometimes the evergreen rhododendron Marseille Menard blooms again in September.
Erato... Shrub up to 1.5 m high with a wide spreading crown. The flowers are large, bright red, lighter on the periphery, with an uneven edge. Erato's evergreen rhododendron - pictured below.
Blooms in May-June. The variety has good winter hardiness and can withstand temperatures as low as -27 ° C.
Alfred... A low-growing variety of evergreen rhododendron, growing only up to 1-1.2 m. The flowers are medium-sized, 5-6 cm, pale purple in color with golden freckles. Collected in caps of 15-20 pcs.
The winter hardiness of the variety is good, up to - 25 ° C.
Lita... A fairly tall dense bush that can grow up to 2.5 m. The flowers are large, with an uneven wavy edge, up to 7 cm in diameter, collected in dense inflorescences of 10-15 pcs. The color is pink with a purple tint, on the upper petal there is a blurry speck of golden olive color. The pink evergreen Lita rhododendron is shown in the photo below.
The variety has excellent frost resistance - up to - 35 ° С.
Humboldt... Katevbinsky rhododendron hybrid. A dense compact bush up to 1.5-2 m high. The flowers are purple-pink, light, collected in dense cap-shaped inflorescences of 15-20 pcs.
The flowers have a characteristic red-brown spot. Winter hardiness - up to - 26 ° С.
Pohyolas Dother (Podjola Dother)... One of the most winter-hardy varieties of evergreen rhododendrons. Finnish hybrid variety. The bush grows to about 1 m. The crown is quite dense and wide. The flowers are light purple, almost white, with a reddish corrugated edge. Collected in inflorescences of 8-12 pcs.
Evergreen rhododendron Pohyolas Dother has excellent frost resistance, it is able to withstand temperatures up to -35 ° C.
Hellicki - another hybrid variety of evergreen rhododendrons of Finnish selection. It is a low compact bush up to 1-1.2 m high. Flowers are bright, juicy, crimson-pinkish, with orange blotches. Collected in inflorescences of 8-12 pcs.
Helliki evergreen rhododendrons have several sub-varieties that differ in color: Red, Helsinki University (pink), The Hague (lilac-pink). All of them are distinguished by excellent winter hardiness - up to - 34 ° C.
Planting and caring for evergreen rhododendrons
In the wild, rhododendrons grow mainly in regions with subtropical and temperate climates. Some species of this shrub are also found on the territory of Russia, for example, in the south of Siberia and the Caucasus. To successfully grow evergreen rhododendrons in other climatic conditions, they will require some care.
Selection and preparation of the landing site
Evergreen rhododendrons do not like bright light, this can provoke foliage burns. Therefore, for planting them, it is better to choose a place where sunlight will be diffused. The site must be well protected from cold winds. The groundwater level should not be higher than 1 m. Evergreen rhododendrons get along well with almost all plants, but it is better to plant them next to those whose roots go to a deeper level. These are pine, larch, oak, apple tree. But with shallow-rooting linden, maple or chestnut, rhododendrons can compete.
Seedling preparation
Evergreen rhododendron seedlings can be purchased at specialty stores or nurseries. They are sold, as a rule, in special containers filled with soil substrate. When choosing a seedling, you should pay attention to its appearance. He should look healthy and have no signs of diseases (yellowing of leaves, white bloom, etc.).
Planting rules for evergreen rhododendrons
Evergreen rhododendrons can be planted in spring and autumn. In spring, you can start planting after the snow has completely melted and the soil warms up to + 8-10 ° С. In different regions, this time may fall on April-May. Autumn transplanting can be done in September-November. Evergreen rhododendron tolerates transplantation well, so you can plant it and transplant it at another time, if it does not bloom at the same time.
The size of the planting hole should be twice the volume of the seedling root system. A drainage layer must be poured onto the bottom. To do this, you can use fragments of bricks, expanded clay, large crushed stone. Regular soil for evergreen rhododendron will not work, therefore, for planting, you must prepare a sufficient amount of soil substrate in advance. It must have a pronounced acid reaction, therefore, it must include high-moor peat and coniferous litter.
On the day of planting, the container with the seedling is spilled abundantly with water. This will make it much easier to retrieve the plant. The seedling, together with a lump of earth on the roots, is placed in the planting hole strictly vertically and covered with soil substrate, periodically compacting it. In this case, the root collar of the plant should be flush with the ground. After the hole is completely filled, the seedling is spilled abundantly with water, and the root zone is mulched with peat or fallen needles.
Informative video about planting and caring for rhododendrons:
Watering and feeding
Evergreen rhododendrons love moderately moist soil, but excessive watering can lead to stagnation of water in the roots and their decay. The state of the leaves can serve as a guide. If they begin to lose their natural shine, then the plant needs watering. Watering evergreen rhododendrons is necessary with rain or settled softened water. A day before watering, you can add a little peat to the container. This will additionally soften the water and acidify it slightly.
Evergreen rhododendrons need to be fed throughout the season. It is best to do this in small portions, but often. It is best to use mullein infusion diluted in water for feeding. Until mid-summer, you can feed the plants with nitrogen-containing mineral fertilizers, for example, ammonium sulfate. Then the nitrogen application should be stopped. Further dressing is done only with potash and phosphorus complex fertilizers, so as not to stimulate excessive growth of green mass.
Pruning
The rhododendron bush is quite dense and compact, therefore, as a rule, it is not formed. Pruning can only be carried out for sanitary purposes, in order to cleanse the plant of broken or dried branches, as well as shoots diseased or damaged by pests. Periodically, the bushes need to be rejuvenated by cutting out perennial shoots and growing younger stems instead. Such pruning of evergreen rhododendrons is carried out in the spring, before flowering, along with other care works. In this case, no more than ¼ of the bush is removed. Large sections must be covered with garden pitch.
Some gardeners remove faded buds by pruning them immediately after flowering.Such a measure helps the plant to redistribute nutrients and direct them not to the setting and ripening of seeds, but to the formation of new flower buds. The next year, the flowering of such bushes will be more abundant.
How to prepare an evergreen rhododendron for winter
Preparing for winter is an obligatory part of caring for evergreen rhododendrons in the fall. In winter, plants can suffer not only from low temperatures, but also from the severity of adhered snow and cold winds. To prevent this, a fence is installed around the bush - a house. Its frame can be made of wire or wooden battens. With the onset of cold weather, the shoots are tied into one bunch and tied to a support. Covering material, for example, burlap, is stretched over the fence. Low-growing varieties with flexible stems can be bent to the ground and fixed. Despite the frost resistance of many varieties of evergreen rhododendrons, such additional measures for the preservation of the bush in the winter will not be superfluous.
The roots of evergreen rhododendrons are located close to the surface, therefore, before wintering, the root zone must be insulated. This can be done with peat, covering it with a layer of 15-25 cm.
Why do the leaves of evergreen rhododendron turn red
Reddening of rhododendron leaves is a completely natural process. There may be several reasons for this phenomenon.
- Age... Often the reddening or yellowing of the leaves in evergreen rhododendron is associated with the natural change of leaves. Leaves live 3-4 years, their redness is a signal that they are gradually dying off.
- Cold... With the onset of the cold season, some types of rhododendrons change color.
- Incorrect fit... Reddening of the leaves of evergreen rhododendron after a short time after planting or transplanting indicates inappropriate conditions for its growth. This can be direct sunlight, lack of moisture, etc.
- Lack of phosphorus... Despite frequent feeding, the plant may feel a lack of this element. You can quickly fill the phosphorus deficiency by spraying the bushes with a solution of potassium monophosphate. This substance is well absorbed by all parts of the plant, but it quickly decomposes, so this top dressing is done several times per season.
Various diseases can also cause changes in the color of the leaves of evergreen rhododendron, but in this case, the color of the leaves often becomes yellow or brown.
Reproduction
Evergreen rhododendrons can be propagated by seeds or vegetative propagation methods:
- cuttings;
- layering;
- dividing the bush.
Seeds can be planted in November or January to March. Sowing is carried out in special containers filled with a mixture of peat, sand, and soil taken from under coniferous trees. The germination rate of rhododendron seeds is good. The substrate must be periodically moistened with acidified softened water, and the growing seedlings must be supplemented with phytolamps, providing them with a daylight hours lasting 12 hours. Plants are kept in containers for up to 3 years, taking them out into the open air only in the summer. Only then are the seedlings planted in open ground for growing.
The seed propagation method is the longest and most laborious, since the seedlings need constant care for a long time. Seedlings can bloom only after 6-10 years.
Vegetative methods of reproduction of rhododendrons are more fleeting. In late spring or early summer, you can reproduce by cuttings. To do this, use semi-lignified plant stems, cutting them into pieces 12-15 cm long. The lower part is soaked for a day in a growth stimulator, after which the cuttings are planted in containers filled with a substrate - a mixture of sand, sour peat and coniferous earth. This soil mixture is best purchased at a specialized store. Cuttings are planted at an angle of 30 °.After that, the substrate is moistened, and the container is covered with a film and removed to a warm place.
Evergreen rhododendrons take root for a long time, from 4 to 5 months. All this time, it is necessary to maintain the optimal temperature (+ 25-30 ° C), as well as high humidity. The process can be accelerated by additional lighting of cuttings with phytolamps, increasing daylight hours to 15-16 hours. As the seedlings grow, they are carefully transferred to larger containers, being careful not to disturb the clod of earth on the roots. Rhododendron is grown for 1-2 years, after which it can be planted in a permanent place.
It is quite simple to get cuttings from the mother shrub of the evergreen rhododendron. To do this, you can use 2 ways:
- Bend several side shoots to the ground, fix with a bracket and cover with a mixture of sand and peat. In this case, the underground part of the stem is split along, and a chip or branch is inserted into the split. This technique provides faster and more active rooting. Regular watering provides the cutter with rapid growth of its own root system. In autumn, the cuttings are not cut off, so as not to weaken before wintering, it hibernates together with the mother bush. The transplant is carried out in the spring.
- Cover the base of the bush with plenty of soil. In this case, some of the lateral stems, with sufficient watering, will take root on their own. In the spring, they can be carefully cut off from the mother bush and transplanted to a new place for growing.
Dividing a bush is a fairly simple way of breeding rhododendrons. In this case, an adult, highly overgrown bush is divided into several parts, a division, each of which has its own stems and root system.
Diseases and pests
Evergreen rhododendrons often get sick. The reason for this may be disturbances in care, weather factors, poor-quality planting material. The greatest danger to these plants is represented by fungal diseases. These include:
- Rust.
- Late blight.
- Spotting.
- Gray rot.
Diseases can be recognized by a change in the color of the leaves, the appearance of putrefactive deposits, white or brown bloom, a modification of the shape of shoots or leaf plates.
In some cases, the plants can be saved by removing the infected shoots and treating the bushes with fungicides. Therefore, examination of rhododendrons must be carried out regularly to detect the disease at an early stage.
Often appear on rhododendrons and pests. These include:
- Furrowed weevil.
- Rhododendron leafhopper.
- Rhododendron bug.
They fight pests by spraying the bushes with insecticides. Affected leaves must be collected and destroyed, as insects are often disease carriers.
Conclusion
Evergreen rhododendron can be a wonderful garden decoration. It is believed that the plant is capricious and quarrelsome, caring for it is difficult and time-consuming, but this is not the case. Most of the difficulties are associated not with the plant itself, but with the inappropriate conditions for its growth. If you follow all the recommendations for choosing a place, requirements for soil composition and care, evergreen rhododendron can be grown completely calmly, even in conditions of not quite suitable climate.
