Hydrangea fertilizer: everything you need to know at a glance

Hydrangeas have a high need for nutrients. Here you can find out whether and why hydrangea fertilizers are really necessary and what the differences are.

The genus Hydrangea includes 70 to 80 species, several of which are very popular in our gardens. They delight almost every observer with their characteristic inflorescences, but some species are real divas when it comes to their location Hydrangea care and nutrient supply goes.

Hydrangeas do not always show their most beautiful side. We explain why hydrangeas benefit from a special fertilizer, what it consists of and how organic, mineral, blue-coloring and organic hydrangea fertilizers differ.

Why do hydrangeas need a special fertilizer?

The nutritional requirements of hydrangeas are very high overall. Of the three main nutrients, nitrogen (N) and potassium (K) are mainly required in larger quantities, while less phosphorus is required. In addition, the need for iron is increased in many species. Some Hydrangea species - about the Velvet hydrangea (Hydrangea sargentiana) and the climbing hydrangea (Hydrangea petiolaris) - react quickly to suboptimal care and nutrient supply with a failure of the flower or frost damage.

In addition to the right supply of nutrients, the properties of the soil or potting soil are crucial for the successful care of hydrangeas. Their high water requirements, for example, call for a humus soil that can store a lot of water. At the same time, waterlogging must not occur, because the plants also suffer from this. Almost all hydrangea species also require a fairly low soil pH. This not only influences the color of the flower Farm hydrangea (Hydrangea macrophylla), but in particular the ability of all hydrangeas to absorb nutrients. An unsuitable pH value of the soil can lead to malnutrition. Since soil properties are influenced by the type of fertilization, choosing a specific hydrangea fertilizer is a practical way of promoting healthy, well-flowering plants.

What is hydrangea fertilizer made of?

Hydrangea fertilizers can be mineral, organic or organic-mineral. While mineral fertilizerContaining only the raw nutrients as quickly soluble fertilizer salts are the nutrients in organic fertilizers bound in natural structures that are only released through biological and chemical processes in the soil. The organic fertilization maintains and nourishes the soil life and can thus improve the soil properties. Organic-mineral hydrangea fertilizers combine both types of fertilizer and therefore have both a high level Speed ​​of action as well as a natural long-term effect with simultaneous maintenance of Soil qualities.

Tip: Because hydrangeas love acidic locations, some special fertilizers even contain substances that acidify the soil. The "alums" are a group of sulfuric acid compounds made up of metal ions, sulfate and water. When alum is dissolved in soil water, the pH value drops due to the release of protons (H.⁺Ions). This effect also leads to the blue bloom in the Farm hydrangea (Hydrangea macrophylla) - but only for a short time. The creation of a constantly acidic environment around the hydrangea has a more sustainable effect. If the soil pH value is not very acidic, the farm hydrangea shows its flowers in classic pink or white.

Hydrangea fertilizers in comparison

The type of fertilization has a strong influence on the vitality of your hydrangeas. But not only the nutrients contained are decisive, as you will find out below.

Mineral hydrangea fertilizer

Mineral hydrangea fertilizers in liquid and solid form provide a precisely defined range of nutrients. In addition to nitrogen, phosphorus and potassium, they sometimes also contain a selection of trace elements. It is possible to supply your hydrangeas with such a fertilizer, but with regular use, the following negative effects occur:

• The micro-nutrient stores in the soil or in the pot substrate can be depleted, causing deficiency symptoms that are difficult to identify in the plant.
• The high concentration of nutrients promotes the breakdown of humus, but no new material is entered to build up humus. As a result, the humus content of the fertilized soil and, at the same time, its quality decreases.
• If used incorrectly, mineral fertilizers can also cause fertilizer damage: susceptibility to frost and failure of bloom are possible.

Blue hydrangea fertilizer

Because the almost glowing blue color of farm hydrangeas inspires many garden owners, they are ready to buy so-called "blue-colored" hydrangea fertilizers or "blue hydrangea fertilizers". These acidify the soil for a short time with aluminum sulphate. It can even be purchased pure, so you can make blue-colored hydrangea fertilizer yourself. However, caution is required when using it: aluminum is a cell poison that damages plant roots. It only becomes available at low pH values ​​and, in too high doses, can severely inhibit root growth. More about Hydrangeas turn blue find out here.

Note: When you find out more about the right one Fertilizing hydrangeas want to learn, we share our professional tips with you here.

Organic hydrangea fertilizer

An organic fertilizer for hydrangeas fertilizes the soil as well as the plant. The organisms in the hydrangea's root space are nourished and release the fertilizer nutrients for the hydrangea. In addition, the material introduced is built up into new humus molecules in the course of humification. In this way, any degraded humus is replaced and the soil qualities that are so important for the hydrangea - water retention capacity, soil aeration and nutrient availability - are promoted. One problem with organic hydrangea fertilizers, however, can be that they work slowly. Predictive fertilization is necessary because the release can take up to a month depending on the weather and the associated microorganism activity.

Organic hydrangea fertilizer

Organic fertilizers are organic-mineral fertilizers with an organic certificate. Like all organic-mineral fertilizers, they combine the advantages of the two opposing types of fertilizer, but for the most part rely on organic components. The mineral components serve to supplement and optimize the effect and must also be permitted in organic farming. Our Plantura organic hydrangea fertilizer carries such an organic certificate. In addition, only vegetable raw materials are used. The production is thus many times more environmentally friendly and the application is a broader mass of users Possible even without a guilty conscience - because this fertilizer has nothing to do with resource-devouring factory farming to do. The nutritional content is adapted to the special needs of hydrangeas and in addition to the main and In addition, iron is contained in a somewhat higher dose of micronutrient elements to counteract the common iron deficiency Prevent hydrangeas.

More information about our animal-free Organic hydrangea fertilizer You will find here.

Make hydrangea fertilizer yourself: fertilize hydrangeas with coffee grounds and Co.

Bargain hunters can also make fertilizer for hydrangeas themselves. Manure manure, for example, works quickly and is rich in all three main nutrients. Extra iron can be brought in with a nettle liquid manure. The production of these liquid manure takes a few weeks each. Aside from a little patience, you don't need much more than a large, watertight vessel - a mason's bucket, for example. compost is not necessarily suitable for hydrangeas: it often has a pH value that is too high, which is the case with the genus Hydrangea can lead to nutrient absorption problems. But you can still use your organic waste to fertilize hydrangeas: all in one Bokashi bucket instead of composting, fermentation takes place. The lactic acid bacteria contained in it acidify your organic waste. The result can, for example, be hidden under a layer of mulch around the hydrangeas. Due to the fermentation in advance, the surface composting then takes place very quickly and nutrients are provided.

Last but not least, we would like to introduce you to a self-made hydrangea fertilizer that is absolutely suitable for everyday use: Coffee grounds from the French press or the filter are slightly acidic and provide less nutrients Dimensions. Together with a nutrient-rich fertilizer, however, it forms the perfect basis for humus formation and thus for Soil improvement around your hydrangeas. More precise information on Production of own fertilizers can be found in our associated special article.