The top 3 recommendations and buying guides

Our recommendations

The COMPO Rhododendron long-term fertilizer is not only suitable for rhododendrons, but for all types of bog plants. With a share of 16 percent it contains a lot of nitrogen, which is indispensable for healthy and strong growth. With a phosphorus content of 14 percent, it also ensures that blooms are as magnificent as they are long-lasting. Potassium and magnesium, in turn, strengthen the plants' defenses and are important for healthy foliage and strong green leaf color. Due to the three-month long-term effect, one fertilization per season is sufficient, which is ideally carried out at the beginning of the shoot. The nutrients are immediately available to the plants.

The rhododendron and Hydrangea fertilizer from Dehner not only impresses with its comparatively low price, but also with its mode of action. The fertilizer contains both organic and mineral ingredients. Some nutrients are immediately available to the plants, others only develop their effectiveness later. This ensures an even supply of nutrients, which also promotes Rhododendron fertilizer by adding earthworm humus and mycorrhizal fungi, the soil life and thus the natural soil fertility. The 2-kilogram pack is sufficient for approx. 25 square meters. Ideally, you should apply the fertilizer two to three times a year, the first time before flowering (at the end of March).

Inexpensive, comes in a large package and without any frills Rhododendron fertilizer from the manufacturer Oscorna: Exactly the right product if you have a lot in your garden Rhododendrons, Hydrangeas and other bog plants. This fertilizer is also suitable for azaleas, heather and related plants cultivated in pots. The Oscorna rhododendron fertilizer consists of 75 percent organic components of both animal and vegetable origin, which ensure a natural long-term effect. In addition, these activate the soil life and thus stimulate the natural formation of humus. In addition to the plants mentioned, the product is also suitable for supplying blueberries (blueberries).

Purchase criteria

scope of application

Rhododendrons and their related azaleas are planted in the garden, as a container plant on the balcony or terrace, and as a houseplant (v. a. Indian azalea, Rhododendron simsii) cultivated. Depending on the type of cultivation, different rhododendron fertilizers are used. For indoor azaleas, for example, you should use fertilizers that are especially suitable for flowering indoor plants. On the other hand, you can use rhododendrons in the open air with rhododendron fertilizer in liquid or in In the form of granules, brands with a predominantly organic composition should be used prefer.

Fertilizer form

Solid fertilizer: Solid rhododendron fertilizers are available as easy-to-dose and virtually dust-free granules that simply worked superficially into the root area of ​​the bushes and then poured vigorously will.

Liquid fertilizer: Liquid fertilizer, on the other hand, is a concentrate that must first be diluted with the irrigation water. It is very easy to administer because all you have to do is water the plant with the enriched irrigation water.

Type of fertilizer

Mineral fertilizer: Purely mineral fertilizers, which some also refer to as synthetic fertilizers, are good to use for indoor plants. For garden plants, on the other hand, they are less recommended because they have a negative impact on soil health and thus humus formation. Their active ingredients are immediately available for the plants, but the agents are also very quickly overdosed and can then also have negative effects.

Organic fertilizer: Organic fertilizers, on the other hand, consist of vegetable and / or animal substances (the latter is often slaughterhouse waste) that slowly decompose in the soil. In this way, the nutrients it contains are gradually released to the plants. Organic fertilizers have a positive influence on soil life and thus on soil health, and over-fertilization is hardly possible. Only in the case of deficiency symptoms is no quick help possible due to the slow release of nutrients.

Mineral-organic fertilizer: Mineral-organic fertilizers combine the advantages of the first two forms, so that both quickly and slowly effective nutrients are available to the plants. The disadvantages of the other forms, however, do not come into play here.

NPK composition

Rhododendrons have a high need for nutrients and only bloom little or not at all if they are not adequately supplied. Rhododendron fertilizers should have a high percentage of nitrogen, as this nutrient is essential for strong and healthy growth. Phosphorus ensures the long-lasting, splendid bloom, which should, however, be contained to a lesser extent than nitrogen - a proportion of around four percent is ideal. Furthermore, potassium and magnesium should not be missing, as these are responsible for healthy foliage and also strengthen the defenses of the shrubs.

Long-term effect

If you don't do it regularly re-fertilize want, the use of a rhododendron fertilizer with long-term effects makes sense. Once fertilized, these provide the plants with all the nutrients they need for four weeks, three or even six months, so you only need to fertilize once, twice or three times a year. With all long-term fertilizers, the first dose is given in spring, before flowering. The month of April is ideal for this. A second fertilization can be done after flowering from the end of May.

PH value

Rhododendrons and other bog plants need acidic soil. It is therefore important that the rhododendron fertilizer is free of any lime additions and that the pH value is kept at a constantly low level. Of course, the fertilizer itself should also have a correspondingly acidic pH. This is usually printed on the packaging.

frequently asked Questions

When and how often should rhododendrons be fertilized?

Rhododendron should at least once a year be fertilized, the first fertilization should be carried out in April. Depending on the fertilizer used - and its long-term effects - fertilize a second time from the end of May. This gift is intended to stabilize the plant after the exhausting flowering. If it has rained a lot, you can fertilize a third time from the beginning of July, but then only with half the recommended dose.

Is rhododendron fertilizer also suitable for other types of plants?

Of course, rhododendron fertilizer is not only suitable for rhododendrons, but in principle for all bog plants. These are plants that have a high need for nutrients and prefer an acidic pH value. That also includes Hydrangeas, various Eriken, blueberries, cranberries, lingonberries etc. You can also optimally supply magnolias with rhododendron fertilizer.

Can I use another fertilizer for my rhododendrons?

A mixture of dried rhododendrons is very suitable for fertilizing rhododendrons Coffee grounds and Horn meal respectively. Horn shavings. Both components are organic fertilizers that slowly decompose and stimulate soil life. In order to avoid deficiency symptoms, you should also use compost for fertilization, whereby you should give preference to deciduous compost due to its acidic pH value. Coffee grounds also acidify the soil.

How much fertilizer does the rhododendron need?

How much fertilizer do you give your rhododendron administer depends very much on the size of the plant. Smaller specimens up to a height of around 60 centimeters are satisfied with 40 to 60 grams of rhododendron fertilizer, while larger ones up to a height of 120 centimeters need 90 grams. Rhododendrons that have grown even higher receive between 120 and 200 grams of fertilizer depending on their size.

equipment

Rhododendron soil

Specific Rhododendron soil contains everything that rhododendrons need for healthy growth. Above all, the special substrate is lime-free and has an acidic pH value - ideal not only for rhododendrons, but also for other bog plants such as azaleas, hydrangeas, blueberries, etc. You can use the substrate not only for potted plants, but also to improve the soil when planting in the garden.