Rhododendron evergreen - description and cultivation
Rhododendrons are considered traditional representatives of territories with a temperate and subtropical climate, while this group of plants is widely used for landscaping the local area. Among all kinds of forms, the so-called evergreen varieties are considered the most popular.preserving foliage throughout the season. The article describes in detail the characteristics of this group of shrubs, as well as a description of its most popular varieties.
Description of Evergreen Rhododendrons
All kinds of rhododendrons are attributed to typical representatives of the Heather family. These are perennial flowering bushes used for landscaping private areas, as well as public spaces.
In turn, the evergreen rhododendron can be called one of the most common and popular species of this group of vegetation. This is a cosmopolitan type of vegetation, the bush is actively used in home gardening almost around the world.
The average representative is a branched shrub with a dense and spreading crown. Plant height can be varied - there are all kinds of undersized and ground cover forms up to 30 cm long, as well as tall, half tree-like specimens reaching a vertical growth of several meters. The root system of the rhododendrons of the fibrous type, the bulk of the roots is in the upper horizons of the substrate.
The main distinguishing feature of such rhododendrons are dense, leathery leaves of a perennial type. Throughout the year, they are distinguished by a rich green tint, while even in winter they remain on the bush. When they enter seasonal suspended animation, they twist, and then, as they warm, they return to life.
Did you know? In Japan, rhododendrons were nicknamed the "bushes of temptation." This is due to the fact that some of their varieties release specific substances into the air, which, when inhaled, lead to slight intoxication.
Depending on the variety, the size and shape of the leaf blade may vary, and slight pubescence may form. Representatives of this group are characterized by flowering. During the growing season, the shoots are covered with large, bisexual flowers (up to 16 cm long) bell-shaped type.
The flower can either grow alone, or form large brushes or corymbose inflorescence. At the end of flowering, the ovary remains on the shoots, from which the fruits are subsequently formed. They are five-leafed boxes with numerous seeds.
In crop production, there are many different varieties of this group of plants, but not every one of them can be called really successful and popular among gardeners. This is often associated with both individual care requirements and winter hardiness. Below we will consider the most popular varieties of the evergreen rhododendron, as well as their main differences from related hybrids.
This variety is considered one of the most popular. It differs in rather large leaves, as well as resistance to all kinds of weather conditions, while it is able to successfully grow on the site for several decades. The flowers of the variety are quite large, gather in characteristic inflorescences of 15–20 pieces.
The plant looks most spectacular during flowering, during this period the bush acquires the most spreading form, as well as round outlines.At the same time, green foliage looks quite contrasted against the background of red, pink, raspberry and purple flowers.
The plant is a hybrid form of the Katevbinsky rhododendron. The average representative of the variety is distinguished by a rather tall stalk, about 2 m high. The leaves on the shoots are small, light green in color, shiny.
During flowering, the shoots are covered with small funnel-shaped flowers up to 5 cm long. The petals have a fairly saturated lilac-pink hue, on top of which an orange spot forms. Individual flowers are collected in large inflorescences of 8-16 pieces.
Variety Karen came into the culture of wild forms, from ancient times grown in Japan. This is an incredibly spectacular, but quite compact plant with small red-purple flowers covered with dark speckles.
The average height of the bush does not exceed 100-150 cm, while the diameter of the crown is about 90-100 cm. One of the distinguishing features of the plant is foliage. In autumn, the green hue changes to saturated purple, which gives rhododendron a special decorative effect.
This variety is derived on the basis of Katevbinsky rhododendron. The hybrid is considered one of the largest, its average height reaches 2.5 m, while the width can be 2–2.2 m.
The maximum decorativeness of the plant occurs during flowering - at this time the bush is covered with large bright pink flowers covered with a small burgundy grains. Individual flowers are collected in racemose inflorescences. Nova Zembla is considered one of the most unpretentious rhododendrons - the plant tolerates drought, as well as seasonal heat.
Marcel Menard is able to safely withstand seasonal frosts down to -25 ° C, which makes it ideal for growing in temperate climates. The bush is medium in size, often its height is up to 1.5 m.
The crown is quite dense, covered with numerous elliptical leaves. During flowering, dark violet flowers appear on the plant, collected in characteristic racemose inflorescences. The main color of the flowers is complemented by a golden ornament.
It is a medium-sized shrub with a spreading crown. The plant height is within 1.5 m, the width is about 1-1.5 m. The shoots of the bush are directed strictly up, which is a characteristic feature of the variety.
The branches are covered with dense leathery leaves of a saturated green hue. During flowering, the crown forms dark red flowers with a corrugated edge. The winter hardiness of the variety is high, the bush is able to withstand frosts to -25 ...- 27 ° C.
Representatives of the Alfred variety are rather compact shrubs, not more than 1.2 m high. The shoots of the plant are covered with large leathery leaves of an elliptical shape. The upper surface of the leaves is darker than the lower, which is a characteristic feature of the hybrid.
Did you know? The center of distribution of rhododendrons around the world is considered to be Great Britain, it was in this country (1800) that the first hybrid of the plant appeared.
This variety blooms profusely and amicably, during this period the crown is covered with small flowers up to 5 cm long. The main shade of the petals is purple, it is complemented by greenish-yellow spots. Flowers are collected in 15-20 pieces, forming large racemose inflorescences.
The Lita variety is primarily known as a large, long-standing shrub up to 2.5 m high. The shoots of the plant are quite powerful, during flowering they are covered with large flowers about 7 cm long. The flowers are combined into small hemispherical inflorescences 12–15 cm in diameter.
The main shade of flowers is violet-pink; small dark green spots form on top of the main color. The plant is considered the most winter-hardy of all varieties of rhododendron; it can easily tolerate seasonal frosts down to -35 ° C.However, when grown in the Urals, it necessarily requires shelter for the winter.
Humbolt is a medium-sized shrub up to 1.5–2 m high. Its crown consists of large and branched stems covered with elliptical leathery leaves up to 12 cm long. The flowers of the plant are also large, about 8 cm long.
The color of the petals is saturated, purplish-pink tones, each flower has a small dark red spot. 15-20 flowers are collected in small racemose inflorescences. The shrub is quite winter-hardy, under light shelter from the spruce he can withstand frosts to -26 ° C.
Pohyolas Doter (Arson Doter)
It is a compact and winter-hardy variety, with an average bush height (about 1 m). The crown of the plant is dense and wide, formed from thick shoots. During flowering, the bush is covered with small light purple or white flowers.
Each petal has corrugated edges, and also features a rich red border. Flowers are collected in 8-12 pieces in small racemose inflorescences.
Helliki is considered the best hybrid variety of Finnish selection. This plant is a small bush with a height of not more than 1 m. It differs in incredibly exquisite flowers of a saturated pink or pink-raspberry hue.
An orange ornament forms on top of the main color. The plant forms large inflorescences of 8-15 individual flowers. Helliki has several sub-grades at once that can withstand frosts down to -34 ° C.
Landing and further care
Wild rhododendrons are often a typical flora of warm subtropical zones. At the same time, all kinds of hybrids feel great in the temperate climate zone, up to the Urals. However, in order to grow a truly flowering and healthy plant, a specific planting procedure is required.
This group of shrubs does not tolerate open sun.therefore rhododendrons are planted only in partial shade, in areas with diffused light. Also, the place under the future flowerbed should be protected from drafts and sudden gusts of wind. He does not like plants and high humidity, so the place should be distinguished by a substrate with low moisture capacity, and also have a groundwater level of at least 1 m.
Important! Before you buy a seedling, you should definitely pay attention to its appearance. High-quality planting material has no signs of damage by pests or fungi, while it differs in an elastic and moist rhizome.
They begin to plant shrubs in spring (mid-April - May) or in autumn (throughout October). Seedlings are planted in well-fertilized soil, for this, about 2 weeks before planting, it must be well fertilized with humus, peat, compost or rotted manure. After this, the soil must be carefully plowed to a depth of at least 30 cm.
Perform the procedure according to this algorithm:
- For 1-2 hours, soak the seedlings in clean water, at room temperature.
- Create a landing hole 70 cm wide and 50 cm deep on the plot.
- Lay a layer of broken brick or small gravel (10 cm) at the bottom of the pit, and then peat (10–20 cm thick) fertilized with 40–60 g of garden sulfur.
- Place the plant in the hole - do this so that the root neck is approximately at the same level with the area of the site.
- Fill all the cracks between the root system and the ground, and then firmly compact the soil.
- Form around the sapling a 5-cm-deep tree trunk circle and water the plant (after about 2 weeks, the tree-trunk circle should be leveled to the level of the flower bed).
To enjoy the rhododendron and its exquisite flowers for many years, the bush must be surrounded by specific care. It provides for a standard set of agrotechnical procedures that allow you to create the most optimal microclimate on the site.
This will require:
- water the flower bed at least 3 times a week, during summer drought, the frequency of watering is increased.The water consumption rate for an adult plant is 10–20 l, for a young one - about 5–12 l;
- the day after watering, it is imperative to loosen the soil to a depth of not more than 10 cm;
- from the second half of April to the end of July, feed the bush with nitrogen-containing mixtures every 2 weeks; for this, a mullein solution (1:13) or ammonium sulfate is used;
- pruning only in early spring or late autumn, while pruning is recommended no more than 1/4 of the total volume of the bush;
- in the second half of October for the winter mulch the trunk circle, and then cover the branches with spanbond, hay, straw, lapnik, etc.
Important! Only acidic water with a pH value of 4–4.5 is suitable for irrigation of rhododendrons. To do this, before watering in a liquid, you need to dissolve citric acid (3 g per 10 l).
Rhododendrons can multiply as vegetative way (parts of the bush), and generative (seeds), while the first is considered the most profitable and simple.
This is explained by the fact that only it allows you to instantly get young seedlings capable of active growth and development, while seeds to dive into open soil require at least 6-10 years. Therefore, the bush is most often propagated by cuttings.
- Around mid-April, cuttings of 10-15 cm long should be cut from half-lignified shoots.
- The 24-hour cut-off location is soaked in any growth stimulator (Kornevin, Heteroauxin, etc.), and then the shoot fragment is planted in a mixture of equal parts of sand, peat and soil from the coniferous forest.
- Plants together with the container should be covered with transparent polyethylene and placed in a well-lit place with a temperature of +25 ... + 28 ° С.
- After about 4-5 months, each seedling will take root, after which they need to be planted in individual containers with a depth of at least 15 cm. Cuttings are grown for about 1-2 years (without shelter), after which they can be planted in open soil.
You can get seedlings and layering. To do this, it is enough to make several longitudinal cuts (upward) in a large lower shoot, insert a match into them, and then dig them to a depth of 2-5 cm.
About a year later, young shoots will appear at the site of each section; after they reach a height of 15–20 cm, they can be separated (along with a fragment of the mother branch) and transplanted.
Diseases and Pests
Hybrid rhododendrons often have good immunity against all kinds of diseases. However, if all the requirements of the bush for care are not observed, it may be affected. spotting, gray rot, rust or late blight.
Infected shoots are immediately cut off, after which they are sprayed with any complex fungicide. The most popular with this option is considered a solution of Bordeaux mixture.
The most dangerous problem in the garden are pests. Among them, foliage and shoots are especially eager to hit. weevils, cicadas and bed bugs.
It is not easy to overcome their distribution, but it is possible - it will take 2-3 times (with a gap of 14 days) to spray the affected plantings with any complex insecticide.
Evergreen rhododendrons are exquisite flowering shrubs that are ideal for private landscaping and decorating the urban environment. Today, there are a huge number of different varieties of this group of plants, so almost everyone can find a suitable option for themselves. However, it is not so easy to grow rhododendron, for this you will definitely need to not only plant a bush in a favorable place, but also surround it with special care throughout the growing season.