Rhododendron Grandiflorum: description, winter hardiness, planting and care

Rhododendron Katevbinsky Grandiflorum is one of the most beautifully flowering evergreen shrubs. The homeland of the Katevbin rhododendron is North America. Many varieties have been created on the basis of Katevba rhododendron, including the most common Grandiflorum. The species was one of the first introduced to European territory, since it is distinguished by good adaptation to climatic conditions and frost resistance.

Description of rhododendron katevbinskogo Grandiflorum

Rhododendron hybrid Katevbinsky Grandiflorum belongs to the Heather family. One of the oldest varieties of rhododendron, obtained at the beginning of the 19th century. Forms a spreading, highly branched bush 2-4 m high. The shrub is fast-growing, the annual growth is 8-12 cm. Forms a semicircular, dense crown. The size of the Katevba rhododendron Grandiflorum is 2-3 m in diameter. It can grow in one place for about 100 years.

The shade of the bark is brown. The leaves are medium, elliptical, 7-8 cm long. From above, they are dark green, shiny, smooth. Below they are pale, leathery, without pubescence. The inflorescences are compact, uniting 13-15 flowers each, 6-7 cm in size. In the photo of the Grandiflorum rhododendron, a lilac shade of flowers is visible with the presence of an orange spot on the upper petal with splashes. The stamens are long, curved. Flowers without aroma. The buds bloom in early summer.

Winter hardiness of rhododendron katevbinskogo Grandiflorum

The winter hardiness of an evergreen shrub is high, up to -32 ° C, it does not shed leaves for the winter. In winter, moisture from the leaves continues to evaporate, so before the soil freezes, the plant continues to be watered moderately. The leaves react to a decrease in temperature by curling and drooping. Thus, the plant reduces moisture evaporation.

Growing conditions for rhododendron Purpureum Grandiflorum

Rhododendron hybrid Grandiflorum is grown in single or group plantings. It is undesirable to plant shrubs next to trees with the same superficial root system. Stronger plants will depress the rhododendron.

Evergreen shrubs need protection from drying winds and drafts as well as the hot midday sun. To do this, next to the Katevba rhododendron, hedges are created or shrubs are planted in the partial shade of structures and conifers.

For the successful cultivation of evergreen rhododendron Grandiflorum, acidic soils are needed. In the absence of such soil on the site, it is created anew in a large planting pit or, laying a whole area to create a heather corner. Pine litter gives an acidic reaction: cones, branches, needles. And also moss and top peat, which has a red color. Such a substrate will be constantly needed during the cultivation of rhododendron.

Planting and caring for rhododendron Katevbinskiy Grandiflorum

Katevba rhododendrons will not develop in flooded, swampy areas. Shrubs need loose, drained soils. The soil around should always be mulched and not dry out.Plants are treated well. It is carried out in early spring before the buds awaken or in the fall before the onset of frost. According to reviews of the Katevba rhododendron Grandiflorum, seedlings with a closed root system can be transplanted throughout the summer period.

Selection and preparation of the landing site

The site for the rhododendron of Katevba Grandiflorum is chosen taking into account the long growth of the shrub in one place and its further growth along the crown of more than 2.5 m. Rhododendron successfully coexists with its species, as well as coniferous and heather crops, which are similar in demand for the acidic reaction of the soil.

In a group planting between the Katevba rhododendron Grandiflorum and other trees and shrubs, a distance of 0.7 to 2 m is observed, depending on their size.

Seedling preparation

When removing the seedling from the container, you can see that the roots in contact with the walls of the container died out and formed a felt layer. When planting in the ground, young roots inside the earthen coma will not be able to break through the formed barrier. The plant in this case will not develop and will die.

Therefore, before planting, make several cuts or completely carefully remove the dead layer, including from the bottom. Then the seedling is released into heated melt or rainwater.

Advice! Tap water is not used when growing rhododendron because of its unsuitable composition for the plant.

The earth ball is kept in water until it is saturated with moisture and air bubbles stop appearing on the surface.

Landing rules

The root system of the Katevba rhododendron Grandiflorum is fibrous, located closer to the soil surface and grows more in width than in depth. Therefore, in an area with clay soils, a shallow but wide planting pit is made. At the landing site with poorly moisture-permeable soils, a drainage 10 cm high is poured at the bottom of the planting pit. Expanded clay, broken red brick, pebbles are used for drainage. White bricks or concrete residues are not used due to their calcium content.

Advice! To fill the planting pit, the acidic substrate is mixed with the garden soil removed from the planting pit.

Coarse sand is used for loosening. When planting, fertilizer for rhododendron or complex fertilizer is added to the soil mixture, but without calcium and chlorine.

When planting, the root collar is not buried, but raised 2 cm above the general soil level. After planting, the soil around the seedling is compacted, an earthen roller is poured and watered abundantly, including over the crown. After the soil subsides, it must be poured so that the upper roots are closed. After 2 weeks, the poured roller is leveled.

After planting, the soil is immediately mulched using pine bark. It is necessary to add mulch several times during the season. The protective layer is poured without affecting the root collar. The soil under the rhododendrons is not loosened or dug up.

For the first time after planting, the plants are shaded and often sprayed with water, especially in hot weather.

Watering and feeding

The soil under the Katevba rhododendron is always kept moderately moist, avoiding drying out or stagnation of water in the root zone. If water accumulates after heavy rain, it must be drained away. To maintain the acidity of the soil, watering is carried out once a month with the addition of citric acid or special compositions for rhododendrons. The plant is responsive to sprinkling. It is preferable to use water from reservoirs, rainwater or settled.

In the first years after planting, the plants are not fed. With poor growth of the shrub, first of all, you need to make sure that it is properly planted and that the soil acidity is sufficient.

Top dressing of an adult rhododendron of Katevba Grandiflorum is carried out several times per season:

  1. During the formation of buds, fertilizers with a high nitrogen content are used, intended for spring plant care.Universal formulations are used, for example, azofosku or specialized fertilizers for rhododendrons.
  2. During flowering, they are sprayed with flower growth stimulants, for example, the "Bud" preparation.
  3. From the middle and at the end of summer, fertilizers are used that are suitable for the autumn period, which do not contain nitrogen. Top dressing at this time helps the plant to compact the tissues of shoots and leaves, which will ensure their safety in the winter.

For feeding, liquid and dry fertilizers are used. The plant is watered with liquid fertilizers in the center of the bush. Dry ones are scattered in diameter, retreating 20-30 cm from the center of the bush and sprinkled with soil.

Pruning

The starting pruning is carried out at planting, shortening unnecessarily long shoots and tops with inactive buds. Sanitary pruning is carried out according to the results of wintering. Frozen and broken shoots are removed.

Formative pruning is not required, the shrub independently forms a compact, rounded crown.

Preparing for winter

In the fall, before the onset of frost, the bushes are sprayed with copper-containing preparations for the prevention of diseases. The shrub is spud up with high-moor peat to a height of at least 15 cm. The evergreen shrub Grandiflorum is able to winter without shelter. But in this case, he is exposed to winter sunburn and desiccation. In spring, a brown stripe forms on the damaged leaves along the middle vein. Without shelter, the stems can be damaged by the snow mass.

Important! In severe frosts, the uncovered rhododendron dries out, the kidneys are damaged, the plant may die.

Therefore, to preserve the bush, a frame is built and covered with a non-woven covering material.

In the spring, it is advisable to remove snow from the bushes and divert accumulations of melt water. This is necessary so that the soil under the bushes warms up as early as possible. At the same time, the old mulch is removed by hand, without using garden tools, so as not to damage the root system located close to the soil surface.

Reproduction

The rhododendron katevbinsky Grandiflorum is propagated by seeds and vegetatively. Cuttings are taken from semi-lignified shoots from the second half of June. For cuttings, cut off a shoot 5-8 cm long, remove the lower leaves, leaving 2-3 pieces at the top. The cuttings are hard to root, so they are first kept for 12-16 hours in a growth stimulator.

Further, they are germinated in containers with a wet sand-peat mixture. The evergreen species of rhododendron Grandiflorum takes root for about 3-4.5 months. In winter, the seedling is stored in bright, cool rooms, in summer it is grown in the garden for about 2 years.

Diseases and pests

In the description of the rhododendron Grandiflorum, it is said that the shrub does not have specific diseases and pests. The crop is damaged by common garden diseases and pests, especially when grown under inappropriate conditions. For the prevention of fungal diseases, fungicides are used in spring, at air temperatures above + 5 ° C. The treatment is repeated after 2 weeks. When processing, the drug is applied to the outer and inner sides of all leaves, and the soil is sprayed around the shrub.

Important! Rhododendron Katevbinsky Grandiflorum is susceptible to leaf chlorosis.

With metabolic disorders and a lack of iron, spots appear on the leaves. Prevention and treatment of chlorosis in different dosages is carried out with iron-containing preparations.

Leaf-gnawing and other insects are eliminated by treating bushes with broad-spectrum insecticides, as well as acaricides. For slugs and snails, use the drug "Thunderstorm".

Conclusion

Rhododendron Katevbinsky Grandiflorum is one of the suitable varieties for growing crops in Russia. For a rhododendron, the initial choice of a suitable place and the correct planting are important; in the future, caring for the culture is not difficult. Some gardeners grow the Katevbinsky rhododendron Grandiflorum without shelter for the winter, since the variety is winter-hardy.

Reviews of the hybrid rhododendron Purpureum Grandiflorum

Ekaterina Belozerskaya, 45 years old, Tver
In order to grow the Katevbin rhododendron Grandiflorum on its site, it was required to free a whole corner. The shrub grows to a small tree. In addition, having planted one rhododendron bush, in the future there is a desire to supplement it with other heather. It is necessary to select a special, quiet place, so that there are several hours of sun, but the main time is diffused shadow and, of course, acidic soil. The Katevbinsky rhododendron Grandiflorum is one of the most beautiful shrubs.
Christina Pavlova, 47 years old, Alexandrov
Rhododendron Katevbinsky Grandiflorum was one of the first planted in the garden, because it is well suited for our climate, it does not freeze in winter. The very first spring flowers form an adult tree in the form of an excellent, lilac cap. The orange spot and blotches on the middle petal add a special charm, as do the playfully curled stamens. Unblown buds are collected in a cone, somewhat reminiscent of an artichoke.
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