Flower garden and landscape

Rhododendron Reproduction


The standard of decorativeness and splendor of flowering, a magnificent garden rhododendron for many gardeners remains only a dream. The reputation of the exclusive plant has generated a lot of rumors about the difficulty of growing, and low winter hardiness, and poor adaptation to the conditions of the middle lane. And none of these rumors is justified, like the myth that rhododendrons cannot be propagated by yourself. Rhododendrons can be grown from cuttings, layering, and even from seeds, receiving a luxurious flowering shrub at minimal cost.


The variety of rhododendrons is so great that in addition to the "southern" species there are dozens of varieties and thousands of varieties that are perfectly adapted for cultivation in regions with severe winters. Among rhododendrons, there are even such species that feel good north of the middle latitudes. Long-lived, slowly growing, but invariably beautiful, these shrubs are the standard of beauty. Dark glossy leathery leaves create a thick, dense, attractive crown, against which luxurious pink, white, red or purple clouds of bloom unfold in spring and summer.

The luxurious appearance of rhododendrons fully justifies the high prices of planting material. Rhododendrons are one of the most expensive categories of seedlings, but each purchase turns into decades of pleasure and with careful selection of growing conditions it always pays off. Even small, young plants are many times more expensive than the more familiar types of flowering shrubs. There is only one way to save money or get a large amount of planting material with minimal cost of funds - to engage in the cultivation of rhododendrons yourself.

Reproduction of rhododendrons is not at all a complicated process. Of course, due to the fact that the bush cannot be called fast-growing, you will have to wait much longer to achieve full decorativeness than when buying even young "ready-made" seedlings. But then the plants will be better adapted to the conditions of your garden, surprise with increased endurance and unpretentiousness.

The possibilities of choosing methods of propagation of rhododendrons are determined by the characteristics of the plants themselves. Species, or wild rhododendrons, can be propagated vegetatively and obtained from seeds. Varietal rhododendrons, especially modern and new varieties, are most often complex hybrids and are recommended for them to limit themselves to vegetative methods.

Rhododendron bush

Methods of reproduction of rhododendrons:

  1. Sowing seeds for seedlings with growing in containers for several years.
  2. Cuttings.
  3. Layering.

Alternative methods are:

  • separation of bushes used on old, highly growing plants;
  • inoculation of cuttings of rare varieties on stocks of winter-hardy and hardy rhododendrons.

Propagation of rhododendrons by cuttings

Despite the fact that rhododendrons are considered to be slowly growing shrubs, there are no particular difficulties in the process of grafting. Shoots take root in a few months according to the standard method, and plants can bloom even the next year.

Cutting cuttings of rhododendrons is carried out only in the first half of summer (or late spring - for early flowering species and varieties).

For grafting, strong and healthy, semi-lignified or starting to woody annual shoots are chosen. When cutting the cuttings, it is worth leaving the standard apical or stem from the top of the branches of the cuttings from 7 to 10 cm long, and for rhododendrons with a sparse arrangement of leaves - up to 15 cm. For deciduous species, it is better to choose apical cuttings. Lower leaves are necessarily removed from cuttings, leaving only 2-3 upper leaves on each shoot. It is not necessary to shorten the remaining leaves on the cuttings. The slice itself is traditionally performed at an angle of 45 degrees.

Pre-treatment of rhododendron cuttings is reduced to soaking in growth stimulants. Without it, rooting will be slow and the whole process will be delayed. Usually, for this shrub, it is recommended to immerse the lower sections of the cuttings in a solution of any growth stimulator or root for 15-24 hours.

Cuttings of rhododendron.

Any boxes or plates are used to plant rhododendron cuttings, if desired, rooting can be carried out both on a bed in a greenhouse or in a greenhouse, and in open ground, but regular moistening in such conditions is more difficult, as well as controlling the conditions and growth of seedlings. The soil for rooting cuttings must meet the requirements of the shrub itself.

For rhododendrons, only special acidic substrates are used - ready-made earth mixtures for rhododendrons or independently composed soil mixtures of peat, coniferous soil and sand in equal proportions. But if there is no special substrate, you can get by with a simple peat and sand mixture in equal parts.

In the process of planting cuttings there is nothing complicated:

  1. Containers fill the soil and level it.
  2. Cuttings are buried in the substrate, trying to ensure that they are not installed evenly, but at an angle (an angle of 30 degrees is considered ideal).
  3. Cuttings are "squeezed", pressing to the soil and completing the planting by irrigation.
  4. The containers are covered with a glass cap or film, avoiding contact with the cuttings themselves.

Before rooting, the cuttings must be kept at constant temperatures from 25 to 30 degrees Celsius and maintain a stable average substrate humidity and a very high air humidity. To root the rhododendron, it is better to create an environment in which the temperature of the substrate will be several degrees higher than the temperature of the air. Accelerates the rooting process and additional exposure, bringing the duration of daylight hours to 14-16 hours.

On average, the rooting of cuttings in rhododendrons takes from 2 to 3 months. Cuttings are most likely to take root in deciduous rhododendrons, in which the first roots can appear after 5-6 weeks. Evergreen species can take root even 4-5 months. Rooting of rhododendrons is considered high; in 85% of cases, grafting is successful, but there are more difficult rooting varieties and species. In contrast to the growth of aerial parts, a powerful root system is quickly formed in cuttings.

Rooting cuttings of rhododendron.

After rooting, the plants are not transplanted immediately to a permanent place, but into containers, carefully transshipped with maximum preservation of the earth around the roots. For young plants, an acid substrate is required. The optimal soil mixture is a ready-made substrate for rhododendrons or a peat substrate, in which pine needles were added (2 to 1 ratio). Plants are provided with regular watering, preventing waterlogging or drying out of the substrate.

Two weeks after transplantation, the plants are fed with nitrogen fertilizers. Until spring, when it becomes possible to transplant rhododendrons obtained from cuttings into the soil, they are kept in cool rooms with good lighting. The optimum temperature regime is from 8 to 12 degrees.

In spring, plants can be either transferred to open soil for growing, or transplanted into larger containers. For another one to two years, rhododendrons are grown and only then planted in a permanent place.

Rhododendron propagation by layering

The process of rooting rods in rhododendrons is slightly different from the similar propagation method for other flowering shrubs. If other garden pets just bend down and fasten the branch, then for rhododendrons you will have to take care of a few more procedures. Root layers in the spring.

To obtain layering, the rhododendron bush is carefully inspected and allocated to the extreme shoots closest to the ground. Using a large number of branches at the same time is not the best option. From one bush you can root no more than 3-5 shoots.

The process of reinforcing layering itself is quite simple:

  1. On branches in places of future contact with the soil and rooting, it is desirable to make a longitudinal section, splitting the wood in the same way as is usually done on indoor vines. To prevent the cut from closing, a chip or match is inserted into it. Such measures are not necessary, but allow you to get stronger and faster growing plants.
  2. A small hole is made in the place of the bend (depth and diameter about 15 cm).
  3. The branch is bent to the ground and fixed with a bracket or hairpin in the hole.
  4. The shoot is dug up with acidic soil (for example, a mixture of peat and garden soil) and mulched from above with peat.
  5. The remaining tip of the shoot is directed upward, tied to a peg.

To root the shoot, you only need to take care of regular moisture, maintaining stable soil moisture.

Rhododendron propagation by layering

Typically, rooting of layers in rhododendrons gives results in the same year. Twigs fixed in the soil in time form roots and are ready for planting in the fall. But in regions with harsh winters, you should not hurry with planting: it is better to transfer rhododendrons to a new place only next spring, in the standard planting dates, because when separated in autumn, plants will not have time to adapt to winter and may die. To keep the rooted layering until next year, just cover them with dry leaves and spruce branches.

Separation of layering from the mother bush is best done in the spring. The digging is carried out carefully, at a considerable distance, trying not to damage even the thinnest roots and keeping an earthen ball around the new plant. After planting in a permanent place, they immediately mulch and provide the plants (until they adapt) with careful care.

This method also has an alternative option - hilling the base of the rhododendron bush with light acidic soil while maintaining constant soil moisture, which allows to receive a large number of rooted lateral shoots next year without pinning.

Propagation of Rhododendrons by Seeds

Growing rhododendrons from seeds is not an easy task. In the process of sowing itself, there is nothing complicated, and the conditions for young seedlings, although not quite typical, are not difficult to recreate. But the long growing period and the high risk of plant death, as well as the requirement to ensure literally vigilant care, the loss of seedlings as a result of skipping even one irrigation make the seed propagation method the most risky and time-consuming, albeit the most economical. Rhododendrons obtained from seeds will bloom only after 4-10 years.

Sowing of rhododendron seeds is carried out in the spring, in March or the end of February. Germination is maintained well, for several years it ranges from 50 to 80%.

Rhododendron seeds are sown in any containers suitable for sowing seedlings, with drainage holes, spacious, clean, not necessarily low. The sizes of containers are selected depending on the number of seeds: since plants will have to grow for a long time, it is more advisable to limit yourself to one container. For rhododendrons, you can choose any loose, fertile and high-quality substrate for sowing. An ideal medium for growing seedlings is a peat-sand earth mixture or a mixture of special soil mixture for rhododendrons with sand in equal proportions. Before sowing, the soil must be disinfected in any way possible.

Reproduction of rhododendron by seeds.

The process of sowing rhododendron is simple:

  1. Containers fill the soil and level it slightly without tamping. Watering before sowing is not carried out.
  2. Seeds are scattered on the surface of the soil as rarely as possible in order to rid themselves of excess picking and thinning seedlings. Rhododendron seeds are quite small, so sparse sowing requires accuracy or pre-mixing with sand.
  3. Rhododendron seeds are sown on the soil surface without falling asleep with the expectation that future seedlings are at a distance of 1-1.5 cm from each other.
  4. If the containers with crops are not large, they are watered through a tray, allowing the entire substrate to be saturated with acidified or soft water. Excess moisture must be allowed to drain freely. Crops in large containers are watered in the usual way, acting gently.
  5. Crops are covered with film or glass.

The conditions for germination of rhododendron seeds should be as close as possible to average room temperatures. Usually, the first seedlings appear a month after sowing, but if the seeds are fresh enough, they can sprout together in less than three weeks. High air humidity and constant substrate moisture are very important.

The most difficult part in the process of growing rhododendrons from seeds begins when a film or glass is removed from containers with friendly shoots. Young shoots need to be moved from heat to cool. The optimal content for rhododendrons is at temperatures from 8 to 12 degrees. If you leave the crops warm, they will be extremely vulnerable to diseases and quickly wither away. Young rhododendrons are watered very carefully, controlling the soil moisture and keeping it constant.

If the bottom watering was carried out during sowing, then to reduce the risk of the spread of rot, the method of not the classical, but the lower watering is used further. If possible, it is better to shoots to provide backlighting.

Strengthened plants are gradually accustomed to fresh air, so that by summer they can be taken out to balconies or to the garden. Spike picking is carried out in June, transferring plants to large boxes with a distance of 1.5 cm between plants.

Placing in the garden for a warm period is considered the best option, allowing you to get more adapted plants. In the open air, rhododendrons are placed in bright areas, but protected from direct sunlight. Rhododendrons continue to be regularly watered through the pan, saturating the substrate with water and letting the excess run off, or in the usual way. Drying of the substrate is very dangerous, as a result of drought, young small shoots most often die, but dampness is also undesirable for them.

Capacities with rhododendrons are transferred back to rooms with a temperature of 8 to 18 degrees with the arrival of the first autumn colds. For young rhododendrons, the optimal daylight hours are 16-18 hours. Therefore, it is desirable to highlight them throughout the winter. Plants are gently watered.

Rhododendron seedlings.

At the end of February or March, the seedlings dive again, replanting to a distance of 3-4 cm. After a second dive, after 2 weeks the first top dressing begins. During the second year of cultivation, the same strategy is repeated with the removal of plants for the summer in the garden and wintering indoors. Top dressing is carried out 2-3 times per season - after a dive and two times during the summer with full mineral fertilizers (one of the top dressings can be made foliar).

Plants are transferred to the soil on seedlings only in the third year after sowing, in the spring. Despite the fact that the Canadian, Japanese and Daurian rhododendrons are capable of blooming already in the third year after sowing, it is better to remove all buds and stimulate the development of a strong vegetative mass. During the season, 2 top dressings are carried out - one after transplanting, the other - in the summer, providing plants with mulching, weeding, loosening of the soil and regular watering in drought.

Rhododendrons obtained from seeds are transferred to a permanent place in the fourth or fifth year.

Landing of young rhododendrons in a permanent place

For rhododendrons obtained from seeds, cuttings or other methods, the place of cultivation is selected equally carefully. Plants do not like direct sunlight and windy areas.They choose secluded, sheltered places with diffused bright lighting or partial shade, placing rhododendrons under the canopy of trees or on the north side of buildings and objects of small architecture. Usually rhododendrons "combine" with conifers. These shrubs prefer loose, nutritious and high-quality soil mixtures with a pH reaction from 4.5 to 5.0. Clayy, dense, heavy, moist or moist soils with a risk of stagnation of water or a high level of occurrence of groundwater are not suitable for them.

Rhododendrons, regardless of the method of reproduction in a permanent place, are best planted in the spring. For planting, a soil mixture of peat, leaf soil and coniferous litter is prepared in advance. A portion of full mineral fertilizer must be introduced into the soil and digging planting pits with a width and depth of about 60-70 cm. For a shrub, lay a high drainage layer of unknown materials. The landing distance depends on the future size of a bush of a given variety or species and ranges from 70 cm for the most compact rhododendrons to 2 m for the largest.

The most difficult part in planting rhododendrons is to monitor the level of deepening of the root neck. Even taking into account the shrinkage of the soil, it is necessary to install a seedling in the planting pit so that, as a result, the root neck is 2-3 cm above the soil line. A watering hole is immediately created around the landing pit, completing the planting by abundant watering and mulching from needles or peat.

Planting a young rhododendron bush.

From the very first weather, after planting in a permanent place for plants 2-3 times a year (in early spring and after flowering), full mineral fertilizers are applied. In drought and with signs of lack of water, the bushes are additionally watered abundantly. The layer of mulch in the near-stem circle is best maintained constant. Loosening the soil is carried out shallow, after irrigation or heavy rainfall, regularly weeding the weeds. In the first year after planting in a permanent place, rhododendron bushes are not allowed to bloom.

Before the arrival of the first frosts, water-loading irrigation is carried out. In the first and next two years, plants are covered with spruce branches and dry leaves, deciduous rhododendrons bend to the ground. If the variety requires a more reliable shelter, it is carried out in compliance with all the rules of agricultural technology. The plants obtained from the seeds are less winter-hardy, for the winter they are sheltered with a high earthenware of the base of the bushes and thorough shelter by the spruce branches. Evergreen rhododendrons need to be protected from sunburn.