Which fertilizer for what - you really need them

Created: 08/03/2022, 06:00

For garden, indoor and balcony plants there is an unmanageable amount of different fertilizers in the garden market.

We explain which ones really make sense.

In the garden center you are literally overwhelmed by the variety of fertilizers.

Whether hydrangea fertilizer, tomato or lawn fertilizer, for almost every houseplant and not to forget the lawn, there are countless different mixtures, all of which promise a lot.

But isn't a universal fertilizer sufficient here, which can be used for the most common types of plants?

What is the difference and what should be considered when buying?

Various fertilizers for garden, house and balcony plants (symbol image).

© Rust/Imago

Universal fertilizer: all-rounder with a wide range of nutrients

As the name suggests, universal fertilizers should do justice to as many types of plants as possible.

Industrially produced complete fertilizers, including the popular blue grain, contain nutrient salts such as nitrate, phosphorus and potassium.

The nutrient content is printed on the respective packaging according to the so-called NPK formula.

Many complete fertilizers also contain different amounts of sulphur, calcium, iron and magnesium.

Trace elements such as zinc, boron, manganese, molybdenum, copper and cobalt can also be included.

Rule of thumb for nutrients

Nitrogen for leaf growth, phosphorus for flowers and fruits, potassium for plant cell strength.

As the name "Universal" suggests, this fertilizer has something of all components.

In this way, the plant can take care of itself from this supply.

A disadvantage, however, is that the unused substances can accumulate in the soil and pollute it in the long term.

Organic compound fertilizers provide these nutrients in smaller amounts and do not pollute the soil as much.

Since the substances present are first mineralized by organisms in the soil, there is much less risk of over-fertilization.

Horn shavings or horn meal are suitable substitutes for chemical fertilizers.

This organic fertilizer contains large amounts of nitrogen, which is good for the soil.

Many soils are often polluted with phosphorus and potassium, so that a complete fertilizer does not increase the quality of the soil.

But on the contrary.

Horn shavings are slowly broken down by the microorganisms.

The soil has time to absorb the nutrients.

Fertilizer for green plants and flowering plants

In the case of green and flowering plants, a distinction should be made as to whether it is about leaf growth or fruit formation, for example in the case of tomatoes.

With green plants, attention should therefore be paid to a higher proportion of nitrogen.

Flowering plants, on the other hand, do well with a balanced nutrient ratio.

For potted plants in the garden or on the balcony, liquid fertilizers have proven their worth, the nutrient components of which are immediately available, since these plants cannot take care of themselves from the environment.

If a plant shows an iron fertilizer, for example, which stands out due to young yellow leaves with green leaf veins, special straight-through fertilizers can help.

Plants that get their nutrients from the substrate are less likely to suffer from deficiency symptoms.

Fertilizers should be used with care.

If the deficiency symptoms occur due to a metabolic disease or a shift in the pH value, fertilizer should also be avoided.

Special fertilizer for ornamental plants

Even if the vast majority of garden plants have nothing against complete fertilizer, compost or horn fertilizer, it looks a bit more complicated with ornamental plants.

Ornamental plants that grow in acidic soil, such as rhododendrons, azaleas or blueberries, need a fertilizer that regulates the pH and keeps it low.

It should also be low in salt, low in nitrogen, but high in phosphate and potassium.

Orchids should also get a special orchid fertilizer that is weakly dosed.

Lawn fertilizer with nitrogen: for the green you love

For many gardeners, nothing is as important as a lush green lawn.

It has a particularly high nutrient requirement, because regular mowing and the large surface make it really "hungry".

In order to be able to optimally supply the area with the necessary nutrients, a soil analysis is recommended every three to five years.

At the beginning of the year, a long-term lawn fertilizer with a high nitrogen content should be applied if possible.

A lawn fertilizer with a high potassium value is more suitable for autumn.

This strengthens the grasses in winter.

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Fertilize correctly: compost as an all-rounder

If you have the space for a compost heap in your garden, you should definitely get one.

The compost heap is considered an all-rounder for the gardener.

Enriched with a bit of rock flour, it is the ideal supplier of nutrients for almost all plants with its existing microorganisms and fungi.

The variety of fertilizers in the garden center is therefore justified, since many plants have their own specific needs and cannot fully obtain the nutrient content they need from the environment.

An analysis of the respective floor can ensure the correct selection and application later on.