With proper nutrition, rhododendron is able to please its flowering for a long time. In order to grow this plant on its site, it is necessary to create the appropriate favorable conditions, given its whimsicality to the soil and place of planting. From this article you will learn what types of fertilizers are preferable to use for this shrub, as well as how to apply them correctly.
When to Feed Rhododendron
Rhododendrons are extremely positive about competent, caring care. One of the stages of care is top dressing. If all the rules are followed, then the plant will thank you with a beautiful, plentiful flowering, decorating the garden plot. It is strictly forbidden to neglect fertilizer application. With a lack of nutrients, rhododendron may turn yellow, lose buds, lose its luster and elasticity of leaves.
Also, a lack of necessary elements is indicated by the weak development of shoots. In especially neglected cases, the plant completely dies. Rhododendrons need to be fertilized from the beginning of spring until late autumn. As soon as the period of emergence of buds begins, it is immediately necessary to make fertilizing for abundant flowering. To do this, you need universal formulations suitable for the spring period of care.
The next stage of feeding will be the flowering period. At this time, they need to be sprayed with growth stimulants. After the rhododendron has flowered off and has gone to growth, it is necessary to introduce special top dressing for the maturation of new shoots. And the end of the autumn is considered the final period of introducing useful elements for the development of the plant. Autumn feeds are used at this stage, specially designed to help the plant in preparation for the wintering period.
Did you know? In 401 BC e. General Xenophon led 10 thousand soldiers home after an unsuccessful battle across the Caucasus Mountains, where many rhododendrons grew. After the soldiers had a bite to eat with honey from local bees, they became intoxicated, sick and weakened from the andromedotoxin contained in the Pontic rhododendron pollinated by insects.
There are several nuances when feeding shrubs:
- before top dressing, always rhododendron should be watered;
- it is believed that minimal doses of fertilizer are sufficient for this plant.
Seasonal dressing
Fertilizing rhododendron in spring has two goals:
- help in stimulating the growth of shoots and strengthening the roots,
- stimulation of buds for flowering.
And these top dressings are made in two stages. Fertilizing to help the development of new shoots takes place before active sap flow begins, when the rhododendron awakens after winter. They use saltpeter or organics for such dressing, which enrich the soil. The next step is a few weeks after the first fertilizer application. Potash and phosphorus fertilizers are used to stimulate the laying of more buds.
Some gardeners produce both of these top dressings on the same day with a difference of several hours. The first type of fertilizer is applied as mulch and watered, and the second is sprayed after evaporation of moisture. Summer fertilization contributes to the abundant flowering of shrubs in the next season. Use nitrogen compounds for this and carry out top dressing in early summer. At the end of July, when the growth of shoots stops and buds are laid for next year, experienced gardeners recommend potash-phosphorus fertilizers.
All perennials by the end of summer begin to prepare for winter. Rhododendron is no exception. And so that the process of preparing the bush for winter is completed in a timely manner, from mid-summer, nitrogen should not be present in the formulations introduced. Autumn fertilizers for rhododendron should contain phosphorus, magnesium, iron and potassium. You can also put some types of spring fertilizers with a layer of 5 cm (muck, compost, grasscake, peat, sawdust, pine needles) as a mulch on the trunk circle.
Particular attention should be paid to heather compost, it can be brought not only in the fall, but also put under the bush constantly, with a frequency of several weeks. Shrub thanks active and long flowering. Nitrogen-containing compounds are recommended to be used only during the period when the plant has completely passed into a state of winter dormancy, when stable frosts have been established.
Video: how to feed rhododendrons in the fall
Types of fertilizers for rhododendron
Fertilizers for plants have a good effect on the life of the rhododendron. There are several types of fertilizers for this plant, all of them are different in composition and effect. The shrub needs seasonal nutrition, as well as additional nutrition. This can be mineral fertilizers of organic and inorganic origin, organic compounds, targeted fertilizers, long-acting fertilizers, horn meal and coffee cake.
Mineral complexes
The plant is able to obtain the bulk of nutrients from water, soil, and air. These are the only methods of feeding flower crops. The first thing a flower can get is water and carbon, then: potassium, phosphorus, magnesium, zinc, calcium and many other components. The above components are components of inorganic and organic mineral fertilizers. In turn, they can be both simple and complex.
Important! Fertilizers in long-acting granules are designed for regions where warm weather lasts about 6 months. The use of such top dressing in cold regions leads to the secondary growth of shoots at the end of summer, which will freeze with the onset of cold weather.
A complex consisting of mineral fertilizers - these are several types of elements. The use of monophosphate and chelate is quite common. Each plant is able to synthesize organic elements necessary for life from inorganic, but not every soil is rich in mineral inorganic.
Rhododendrons are considered lovers of acidic soils, which means that fertilizers should also be selected mineral-acidic:
- Superphosphate is used to produce a well formed bud.
- In some soils, an insufficient amount of mineral elements, such as magnesium, is present. Magnesium sulfate is used for such soils.
- For uniform and rapid lignification of shoots, potassium sulfate (20 g per 1 m²) is used.
Fertilizers containing chlorine are not recommended for feeding rhododendrons.
Organic compounds
Organic compositions for fertilizing this genus of plants are presented in liquid form. To do this, prepare a special solution of mullein and water in a ratio of 1 liter per 20 g. Before use, the mixture should be infused in a dark place for up to 10 days. Small particles may remain at the bottom, which are filtered through a dense gauze, after which it can be used. The composition can be absorbed for a long time, so moisten the soil first. In the place of germination, the fertilizer is not laid directly, but at a distance of 25 cm from the shoots.
Fertilizers for Rhododendrons
The choice of dressing should be approached competently and deliberately. Since rhododendrons grow on acidic soils and the pH level is about 5 units, some components of the compositions can only do harm. It is recommended to avoid mineral complexes with a high content of calcium.
Targeted Fertilizer for Rhododendrons
If a composition of rhododendrons, hydrangeas, azaleas and heather is collected in your garden, then targeted mixtures will cope much better with the problem of recharge. This type of fertilizer is suitable for group plants. It includes nitrogen, phosphorus, potassium with additional trace elements.
During the flowering period, the composition of the soil can change, to maintain its balance will help such a complex as "Florovit". Gardeners recommend feeding this product from mid-spring to late summer. Each year, the applied dose of the drug increases.
Long-acting fertilizers
Such top dressing is best for plants, as it receives all the most useful not immediately, but gradually. Most often, top dressings such as Osmocote Pro and Floranid Permanent are recommended. The main component of feeding is nitrogen with the addition of trace elements. Fertilizers are represented by granules in an organic capsule, which work for 5-6 (Osmocote Pro), also 2-3 months (Floranid Permanent). The granule dissolves in the soil and gradually enriches the soil with useful substances. Before use, it is recommended that you carefully read the instructions.
Coffee cake
One of the natural and organic substances used by most gardeners is coffee cake. Its composition is of high quality due to the mass of useful minerals and trace elements. Using cake, you can slightly acidify the soil and enrich it with humus, rhododendrons love this. Only use this top dressing as an addition to something, its one action will not be enough.
Horn meal
Horn meal, as well as coffee cake, is considered a natural fertilizer made from hoofs and animal horns. Due to its composition, it enriches the soil with nitrogen and minerals. Chaff dressing maintains a nutrient balance in the soil. This also occurs due to the slow release of nitrogen.
Features of top dressing during and after flowering
During the formation of the buds, compositions containing such minerals as potassium, nitrogen, phosphorus are added. In garden centers, you can buy ready-made formulations specifically for spring care of rhododendrons, designed to extend the flowering time and strengthen the root system.
Did you know? Among rhododendrons, fairly poisonous varieties are found. Due to the acetylandromedol neurotoxin contained, such plants have a depressing effect on the central nervous system, which can even lead to death.
After the bush has bloomed, approximately in the middle of summer, it needs to be helped to restore its strength for laying the future flower buds for the next year. For this, it is necessary to feed it with a universal mixture of potassium, ammonium and superphosphate. Thus, lush flowering can be achieved in the future. It must be strictly monitored that nitrogen is absent in the formulations introduced during these periods.
Ground Acidification Rules
Rhododendrons prefer acidic soils. It is important to check the acidity of the soil, if it is insufficient - acidification is periodically performed. A suitable pH value for this bush is 3.5–5.5. It happens that thanks to the introduced formulations for feeding, the soil is acidified independently.
Also, if regularly updated pine needles are used as mulch, then this rule remains. Otherwise, additional soil acidification is necessary. If the soil has a neutral or alkaline reaction, it is impossible to do without acidifiers - the plants will hurt, wither away and die as a result.
The following methods are used:
- Coniferous needles as mulch are poured onto the trunk circle with a layer of 5 cm, periodically replacing it with new material.
- Peat is used in the same way as coniferous litter for mulching.
- Vinegar. They can water the bush during any growth period, but this method has a drawback. Because of it, the soil loses its quality, depletes, so the plant can become sick.
- Citric acid has the same disadvantages as vinegar.
If peat and needles are also used as a source of useful substances for the plant, then vinegar and citric acid are used only as acidifiers.
What are the mistakes in fertilizing and how to prevent them
The most important thing in growing plants is a competent and precisely formulated approach to the process. The future life of the rhododendron may depend on your actions. Common mistakes are large doses of top dressing. Large amounts of salts can destroy the plant. It is better to choose fertilizers in liquid form, so you can gradually pour it into the ground, controlling the amount.
Important! The metabolic products of animals and birds should not be used as fertilizers for rhododendron. They are not useful in themselves, and can also destroy the plant.
Not everyone knows that some soils do not have the right composition for growing rhododendron. Because of this, the bush will grow poorly, so before planting, you should make sure the correct soil composition. It is very important not to use a complex mixture when feeding rhododendrons. Composition in which there is calcium and other substances with a calcium content (wood ash, lime), reduce the acidity of the soil. Ignoring this rule can stimulate the development of chlorosis in plants.
If you follow the rules for caring for rhododendron, it will delight with its flowering for a long time. Feeding can be used of different types, the main thing is that the plant does not suffer from a lack of useful trace elements and minerals. The condition of the plant, as well as the amount of flowering, depends on the right fertilizer in the first place, therefore it is especially important to observe the rules and principles of fertilizing the plant in spring and summer.
