Rhododendrons in the Leningrad region: the best varieties, cultivation

Rhododendron is a very attractive plant. The flower deserved the attention of gardeners for its amazing lush flowering. It can only be achieved with proper planting and proper care of the plant. I would like such beauty to be on the site even in a region with a difficult climate. Many do not dare to grow rhododendron, considering the plant is not frost-resistant enough. Therefore, planting and caring for rhododendrons in the Leningrad region is an important topic for gardeners in the North-West region.

Features of growing and caring for rhododendrons in the Leningrad region

Flower growers are concerned about the information that rhododendrons require special care and do not tolerate winter frosts well. However, in the Leningrad region there are gardens with mass plantings of these beautiful plants.

The key to successful cultivation of rhododendrons in the gardens of the Leningrad region is the competent selection of varieties. The choice should be among winter-hardy species, and then they need to ensure proper planting and further care. Under natural conditions, the culture prefers to grow near forests and swamps. You can equally often meet both single plants and large group plantings of rhododendrons.

Now there are many hybrids bred by breeders in order to obtain the desired characteristics. Therefore, choosing winter-hardy varieties of rhododendrons is not at all difficult.

The best varieties of rhododendrons for the Leningrad region

The flower belongs to the Heather family, which combines many types of trees, shrubs and indoor plants. Gardeners usually grow undersized specimens of rhododendrons, almost creeping along the ground, or huge lush bushes, from 3 to 7 m high. It is divided into three main types – deciduous, evergreen and semi-evergreen.

The best of them in regions with a cold climate are hybrids with a high winter hardiness index. A selection of varieties of rhododendrons for the Leningrad region with a description and photos that tolerate low temperatures well, to help gardeners.

The first of them are representatives of the group of Katevbinsky hybrids:

1. Grandiflorum (Grandiflorum) – lushly flowering rhododendron with bright purple inflorescences. The height of an adult plant at the age of 10 years reaches 1,2-2,8 m. It has spherical inflorescences, slightly flattened, consisting of 12-19 flowers without aroma. The color of the lavender shade with yellow-red marks, the crown diameter is 3,0-3,2 m. A famous variety among gardeners in the Leningrad Region due to its high frost resistance. Withstands temperatures up to -32 °C. Flowering begins in early June.

   

2. Nova Zembla (Nova Zembla) – red-flowered, evergreen variety of rhododendron. Just like the previous type of rhododendron, it begins to bloom from June. The flowers are bright, red-ruby, black blotches inside the petal. Spherical inflorescences of 13-17 original flowers. The flowers have no smell, the leaves of the shrub are dark green, shiny, shaped like an ellipse. Upon reaching the age of 10 years, the rhododendron has a bush height of 1,6-1,8 m, and a crown width of 1,6 m. The maximum height that is recorded for the variety is 2,5 m. Winter hardiness is high, withstands temperatures down to -32 ° FROM.

   

3. Polar night (Pollarnacht, Polar Night) characterized by rapid growth and longevity. In one place, the rhododendron bush grows well and blooms up to 100 years. The plant is powerful, grows up to 2 m tall, the crown has the same size. The decorativeness is very high, the purple color of the flowers gives the plant a uniqueness. In addition to the juicy color, the flowers have spectacular corrugated petals, the color of which changes with the degree of illumination. In the light they acquire a crimson hue, in the shade they become almost black. There are up to 20 pieces in the inflorescence, each ball resembles a bouquet. The height of an adult rhododendron is about 1,4 m. It begins to bloom in the Leningrad region at the end of May, withstands frosts down to −26 ° C.

   

The next selection of rhododendron varieties for the Leningrad region from the Finnish selection group. They are loved by gardeners for their high winter hardiness, low maintenance and beautiful appearance. Withstand a drop in temperature – 30-40 ° C.

1. The Hague differs in compactness and density of a bush. The bush is quite branched, forms a spherical crown of the correct shape. Diameter – 1,4 m. The height of an adult rhododendron reaches 1,5 m. Flowering in the Leningrad region begins in mid-June, the bush is covered with dense inflorescences of a juicy pink color with wavy edges. Red-orange dots on the petals, one inflorescence consists of 15-18 flowers. Frost resistance is high.

   

2. Hellikki (Hellikki) – a variety for planting in the Leningrad region in shaded areas with acidic soil. Young shoots of the bush are soft, pubescent. Young leaves are also covered with white villi. Rhododendron reaches a height of 1,2 m at the age of 10 years. Dark green foliage with bright pink-purple buds make a spectacular contrast with their combination. The inflorescences of the variety are located at the end of the branches, consist of 8-12 funnel-shaped flowers. It blooms from the end of May for a whole month. Withstands frosts down to -34 °C. Does not tolerate waterlogging, but requires mulching of the root zone.

   

3. Helsinki University (Helsinki University) – a hybrid with a very powerful flowering. The height of the bush is 1,5-2,0 m, the diameter of the crown is 1,4-1,6 m. The inflorescences are conical in shape, consist of 12-18 flowers. Located at the end of the run. The flowers are pink with red patches on the petals. A feature of the variety is considered to be a very lush flowering even after harsh winters. Blooms in the Leningrad region since June. The variety is similar to another species – “Haaga”, but the color of flowers and stamens at Helsinki University is lighter. It is considered a hardy variety with high frost resistance (up to -40 ° C).

   

4. Elvira (Elvira) for lovers of low rhododendrons. An adult bush has a height of only 0,6 m with a crown width of 0,6-1,0 m. The inflorescences consist of 6-10 flowers of a cherry-red hue, resembling bells in shape. Each flower has 6 corrugated petals. In the Leningrad region, it blooms from mid-May to mid-June. The rhododendron variety is considered vulnerable in the spring, loves good snow cover. Requires care when choosing a landing site.

   

Planting and caring for rhododendron in the Leningrad region

To grow a chic bush in the Northwest region, certain conditions must be met:

• correctly choose a place for rhododendron;
• pick up a winter-hardy unpretentious variety;
• comply with the landing time;
• properly plant the plant;
• follow the basic steps.

The degree of flowering, health and appearance of the rhododendron depends on the quality of each stage.

When to plant rhododendron in the Leningrad region

Landing is allowed in spring or autumn. The main thing is that this event does not affect the flowering time and 10-15 days before and after it. In order for the plant to develop well, it needs time to get used to the new place and conditions. Spring planting in the Leningrad region avoids the possibility of freezing of a young bush. If it is planned to plant a rhododendron in the fall, then in the Leningrad region it is recommended to take plants with a closed root system for these purposes.

Site preparation

For rhododendron, it is important to choose the right place and prepare the soil. Heathers love acidic nutrient soil and partial shade. Water stagnation is not allowed. Based on these preferences of the rhododendron, a site with natural penumbra is chosen for planting a plant in the Leningrad Region. This may be a neighborhood with conifers, which will cover the young rhododendron from heat and direct sunlight. The north or northeast side of the house is also good. It is not worth the risk, knowing the thermophilic heather, and plant them in bright sunlight. Close proximity to a pond would be ideal.

The second condition for a successful landing in the Leningrad region is the absence of strong winds. If there is no such site, then you will have to cover the bush with a hedge or a decorative screen. Planting rhododendrons completely under the trees is not worth it. Light penumbra does not mean constant shading. It is undesirable for rhododendrons to be adjacent to birch, spruce, linden. But as an addition, pines, oaks and fruit trees are well suited.

The soil in the Leningrad region also needs to be prepared.

The heavy clay structure is especially unfavorable for rhododendrons. If it is planned to plant several plants, then the place is prepared for all at once, and not for each bush separately.

The pit for the plant should be 70 cm in diameter and 50 cm deep. The bottom is covered with drainage to drain excess water. Sphagnum is laid on half the volume, then a quarter is filled with humus mixed with acidic nutrient soil. A good addition to the mixture will be fallen leaves or needles, pine cones. The soil must be loose.

Rules for planting rhododendrons in the Leningrad region

After preparing the pit and laying the soil mixture, the soil must be well watered. If the plant is bought in a planting pot, then it is simply transferred with a clod of earth into the hole. The free space is filled with the remaining soil and watered again. From above, the near-stem zone must be mulched with a layer of 5 cm.

In order to properly plant a rhododendron in the Leningrad Region with an open root system, you will need to remove a layer of soil 1 m thick in the area allocated for planting. Shield the resulting pit from the sides with natural materials. This must be done so that moisture and nutrients remain in the planting area when feeding the bushes. Lay a drainage layer 20-30 cm thick at the bottom. Large crushed stone or broken brick will do. Pour sand on top (10-15 cm).

Prepare a solution of the drug “Extrasol” (10%) and immerse the roots in it for 10-15 minutes.

Gently place the seedling in the hole, cover with soil. In this case, care must be taken not to deepen the root neck.

In the Leningrad region, a transplant option is possible for rhododendrons if young plants are not planted in a permanent place. Transplant bushes in the spring. The second term is the end of summer in August or the beginning of autumn – September. When transplanting rhododendron, it is important to maintain the depth that was at the first planting. Then the plant is surrounded by a layer of moss and needles 10 cm thick.

Watering and top dressing

There are basic nuances of care in the Leningrad region, without the quality implementation of which it will not be possible to grow a luxurious rhododendron bush. When watering, it is necessary to withstand the golden mean. The plant loves moisture, but does not tolerate stagnation. Therefore, you need to monitor the absorption of moisture and maintain the looseness of the soil. If there is stagnation, then good drainage is needed. To balance the flow of moisture, gardeners:

1. Rhododendrons are planted in the Leningrad region on high ridges. They are raised 10-15 cm above the average spring flood level.
2. Be sure to add loam to the soil mixture. It prevents the peat and pine bedding from churning into a ball, which significantly reduces the quality of irrigation.
3. Use melt or rain water. Worst of all, plants react to tap water due to the admixture of chlorine.
4. Periodically irrigate the leaves by sprinkling. This is especially true during the dry, hot months of summer.

Another important event for gardeners in the Leningrad region is top dressing. The most suitable feeding periods for rhododendrons begin in spring at the time of flowering and in autumn, 2 months before the first frost.

It is important to remember that conventional nitrogen fertilizers are ineffective for this type of plant. Gardeners in the Leningrad region need to use special formulations for acidic soils. The first time fertilizers are applied at the beginning of the flowering of the bush. If this is done earlier, then the nitrogen components will negatively affect the development of flower buds. They just start to crumble. The main nuances and nutrition schedule of rhododendrons in the Leningrad region:

1. Nitrogen top dressing at the end of March. 15-20 g of ammonium sulfate is enough for one bush. An alternative would be cow dung infusion.
2. Phosphorus and potassium components are introduced in mid-June. The end of summer is not the best period. If you feed the rhododendrons at this time, they will grow.

In addition, the bushes must be mulched with pine or spruce bark with a layer of 3 cm. However, loosening for rhododendrons is contraindicated due to the proximity of the roots to the soil surface.

Do not use ash, clay or lime when caring for plants. These substances change the acidity of the soil, which will not affect the life of the bushes in the best way. The optimal acidity for rhododendrons is 4,5-5,0 pH.

Trimming

In addition to watering and fertilizing, it is very important to trim the rhododendron.

Pruning involves achieving several goals:

1. Removal of wilted inflorescences. They continue to be pruned until the formation of seeds. Thus, the gardener helps the plant save vital resources and stimulates the laying of new flower buds for the next season.
2. Crown formation. Spring pruning in early March consists of cutting young shoots above dormant buds. At the same time, the crown of the rhododendron is formed in the form of a ball.
3. Updating the bush or reducing the crown. In this case, cut off the shoots under the fork. The thickness of the removed branches is not more than 2-4 cm.

Protection against diseases and pests

In the Leningrad region, rhododendrons can be affected by fungal diseases. The most common are leaf spot, rust, and cancer. The first two diseases are removed with the help of copper sulfate, which is used to treat plants. If the variety has cancer, then the affected shoots are removed and burned. Preventive treatments for the disease are made with Bordeaux liquid twice a year – in spring and autumn.

An important point that leads to infection is a violation of agrotechnical requirements:

• poor soil aeration;
• excessive watering;
• lack of preventive treatments.

Among the pests in the Leningrad region, thrips, scale insects, whiteflies, spider and rhododendron mites, snails, and slugs should be noted. You need to fight them with insecticidal drugs.

Preparation of rhododendrons for winter in the Leningrad region

Frost protection is very important to maintain the vitality of the plant. The methods of shelter in the Leningrad region are slightly different for different types of rhododendrons.

1. Deciduous. The shoots are bent to the ground, but they make sure that the buds do not come into contact with it. Sprinkle the landing sites with dry foliage or peat with a layer of 15 cm. This is necessary to protect the root neck.
2. Evergreen varieties require shelter. It protects plants not so much from frost as from drying out. They begin to cover rhododendrons at the onset of the first frost. Be sure to leave ventilation holes so that the plants do not rot when warming.

The first year, the bushes are covered with non-woven material. Lutrasil, spunbond and frame structures are used. In spring, rhododendron bushes open gradually, in several stages. They start in cloudy weather and continue the adaptation of plants for 10-15 days so that there are no sunburns.

Reproduction

There are only two main methods of propagation of rhododendrons for Leningrad gardeners – seeds and cuttings.

Deciduous varieties prefer to propagate in shifts. They ripen in September. Sowing begins in early spring, after germinating the planting material at a temperature of + 10-15 ° C. Usually it takes 8-10 days. The soil for seedlings is prepared from a mixture of sand, peat and coniferous soil. After the appearance of 2-3 leaves, the seedlings dive, then grow in a greenhouse. Such rhododendrons begin to bloom in 5-10 years.

Lignified apical shoots are suitable for cuttings. The diameter of the cutting is 3-5 cm, the length is 3-4 internodes. For rooting prepare mixtures:

• peat soil + sand (2: 1);
• heather soil + sand (2:1).

The material is harvested in July, leaves must be left at the top of the cutting. The lower end of the cutting is immersed in a solution of Heteroauxin, then placed in the soil mixture. The lower part of the container in which rooting occurs must be heated with warm air. To do this, the containers are raised above the ground. Rhododendrons take root slowly. Transplantation is available only after a year. If the cuttings are immediately placed in the ground, then the first winter they are securely covered. During the period of growth of the cutting, 3 pinches are made.

There is another method of propagation of deciduous rhododendrons, in which they begin to bloom the next year – layering. It is necessary to dig in last year’s shoots and water regularly. Once a month, use a solution of Heteroauxin. The following autumn, the layers are separated from the mother bush.

Conclusion

Planting and caring for rhododendrons in the Leningrad region is available even to beginner gardeners. If you fulfill the agrotechnical requirements and monitor the condition of the bush, then its lush flowering will be a worthy reward for the efforts spent.