Last updated: August 7, 2021

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Anyone with a green thumb knows that fertilising with compost can have a positive effect on the growth and development of many plants. However, the process of obtaining this valuable compost can take quite some time, sometimes even several months to years. To get enough natural fertiliser in your garden faster, you should use a compost accelerator. But not all compost is the same, which is why choosing the right compost accelerator is essential.

So to find the most suitable accelerator for your garden, you need to consider certain factors. We want to help you with our compost accelerator test 2021. To make your decision as easy as possible, we have summarised and listed the most important factors and criteria for finding the best compost accelerator.

The most important facts

  • To get valuable compost, you have to wait many months. Using a compost accelerator will speed up the composting process and can save you time.
  • The ingredients contained in the compost accelerator feed and support the micro and small organisms that live in the compost, which thus work more quickly and drive the rotting process.
  • The market now offers a variety of different accelerators, which differ primarily in their ingredients, consistency and packaging size.

The best compost accelerator: Our picks

Compost accelerators: buying and evaluation criteria

There is a wide range of different compost accelerators, which is why it can seem difficult to find the right accelerator for your own garden.

The following criteria will help you compare the different compost accelerators.


Usually, the different manufacturers offer compost accelerators in granular or powder form. This consistency is particularly suitable as it allows the accelerator to be easily added to the compost and layered evenly.

However, a few manufacturers also offer compost accelerators in liquid form. This consistency also enables uncomplicated and optimal handling and distribution.

Product weight

Compost accelerators are usually sold in bags, buckets or tins. The commercial packaging usually contains 1, 3, 5, 7.5 or 10 kilograms.

If you prefer accelerators in liquid form, you will usually find the product in bottles with a capacity of 1 or 2 litres.

Since the price per kilogram or litre is often comparatively higher for smaller packaging sizes, it is worth comparing the different packaging sizes and prices.


A compost accelerator is actually nothing more than an aid package for microbial activity in the compost heap. To support this, a compost accelerator contains important chemical elements that promote plant growth, but also decomposition:

Element Description
Nitrogen (N) nitrogen is needed by the microorganisms to decompose green material and thus accelerate the rotting process
Phosphate (P) phosphate is important to keep the pH value in the compost heap stable
Potassium (K) potassium in the compost soil, i.e. the desired end product, is essential for the resistance of the fertilised plants

In addition to nitrogen, potassium and phosphate, a compost accelerator often contains the following ingredients:

  • Additional living microorganisms
  • Additional fungal cultures
  • Animal excrement (for example chicken manure)
  • Horn meal and/or bone meal
  • Sulphur
  • Lime
  • Ammonia

Most commercially available accelerators contain ingredients of animal origin. However, there are also many compost accelerators that do not contain animal ingredients.

With a compost accelerator, the microorganisms in your compost receive a kind of booster.

Therefore, it may be worthwhile to read the lists of ingredients carefully and compare them with each other.

Depending on the individual composition of the ingredients, a compost accelerator is suitable for different types of compost. While some products are aimed at compost heaps with a lot of kitchen waste, other accelerators are more suitable for compost heaps consisting of lawn cuttings and/or leaves. It is therefore advisable to pay close attention to the manufacturer's description.

Compost accelerator: Frequently asked questions and answers

People who want to buy a compost accelerator usually have many questions. Below we answer the most frequently asked questions about the topic.

What is special about a compost accelerator and how does it work?

There is no cheaper and more environmentally friendly way to get high-quality fertiliser than your own compost heap. However, it often takes up to a year to produce good humus. This is where the compost accelerator comes in, because it is nothing more than an aid package for your compost heap.

The ideal compost accelerator speeds up the composting process and thus provides you with valuable humus more quickly. (Image source: Manfred Antranias Zimmer / pixabay)

A compost accelerator helps helpful microorganisms to settle. The ingredients of the accelerator also provide better nutrition for the essential micro- and smallest organisms, which thus work more quickly.

The composition of the organic material is also significantly improved. This effect therefore facilitates and accelerates the process of composting considerably and can even save you several months.

How do I use compost accelerators correctly in the garden?

To achieve the best results, it is important to apply compost accelerator correctly. But don't worry: it's really not too complicated.

Ideally, you should start using compost accelerators as soon as you start a compost heap. If you have already missed this point, you can also use an accelerator during the first turn-over.

Simply add the powder or granules to the compost evenly and in layers according to the manufacturer's instructions. As a rule, a layer of accelerator should be spread about every 20 to 25 centimetres.

The optimal dosage of the product depends on the individual product and the respective manufacturer. Therefore, be sure to read and follow the manufacturer's dosage instructions carefully.

What are the advantages and disadvantages of compost accelerators?

The most important function and strength of compost accelerators is the acceleration and support of the composting process.

Once the compost is built, it can take many months and even years to get good compost or humus for your plants. With a compost accelerator you can speed up this natural process of decomposition and get good quality compost much faster.

  • Accelerates composting
  • Easy to use
  • May contain animal waste
  • Attracts pests
  • Cannot be used in parallel with compost worms

Many compost accelerators have animal waste products such as animal meal. Even though these fertilisers with animal components are considered harmless (from a health point of view), vegetarians and vegans might have ethical conflicts. But don't worry: there are also many accelerators that manage completely without animal products.

An intensive accumulation of nutrients can lead to the attraction of certain pests. Besides insects (such as flies), mice or rats can also become a real problem in this way.

If you decide to use an accelerator anyway, you should definitely pay attention to effective pest protection.

Compost worms are a very high-quality and natural alternative to compost accelerators. However, you should avoid using them in combination with certain commercial accelerators. This is because a compost accelerator increases the temperature inside the compost, which in turn drives the worms away or causes them to die.

What types of compost accelerators are there?

The specialised trade now offers various types of compost accelerators. Besides the "normal" accelerators, there are also those with organic quality.

The commercially available compost accelerator

The commercial compost accelerators are just as efficient as their brothers with organic quality. The biggest difference, however, is that the ingredients in these products are often obtained in a less ecologically sustainable way.

  • Acceleration of the composting process
  • Cheaper purchase price
  • Easy to use
  • Not necessarily environmentally friendly and / or sustainable

For example, the animal ingredients often contained in accelerators may come from factory farming. On the other hand, the price is often somewhat lower than the alternative with organic quality.

The compost accelerator with organic quality

Compost accelerators with organic quality are made of natural and ecologically sustainable material and are thus often a more environmentally friendly option to the "normal" accelerator.

  • Accelerates the process of composting
  • Natural ingredients
  • More environmentally friendly alternative to the normal accelerator
  • Easy to use
  • Higher purchase price

On the other hand, products with organic quality are often a bit more expensive - even though they equally support and accelerate the composting process.

For whom are compost accelerators suitable?

It can take months, if not years, to get hold of valuable compost.

It is annoying when fertilising time is coming soon, but your compost is not yet of sufficient quality or simply not ready. The composting process depends on many different factors and can therefore be considerably delayed.

An accelerator is suitable for those who do not want to wait long for their compost.

To avoid this scenario, it is worthwhile to help out with a compost accelerator as early as when you are creating it, or at the latest when you next turn it over. A compost accelerator supports and drives the decomposition of the waste in the composter and thus helps you to obtain valuable fertiliser as quickly as possible.

A compost accelerator is therefore worthwhile for anyone who has little patience, wants to do without expensive artificial fertiliser and still needs nutrient-rich compost for their garden plants in the foreseeable future.

What does a compost accelerator cost?

The cost of different compost accelerators can vary and depends primarily on the following factors:

  • Desired quality
  • Material consistency
  • Quantity
  • Manufacturer

As always, if you value good quality, you will have to dig a little deeper into your pocket. If you also prefer organic quality, the costs will also increase.

The different consistencies of compost accelerator also have different prices. While an accelerator in granulate or powder form is available from about 1 € per kilogram, the prices for liquid accelerators start at about 3 € per litre.

Material consistency price per kilogram or litre
Granulate, powder approx. 1 - 6 €
Liquid approx. 3 - 8 €

The desired quantity also contributes significantly to the cost. Those who buy small quantities also pay an apparently lower price.

But beware: smaller package contents often have a comparatively higher price per kilogram or litre. It can be worthwhile to compare the prices per kilogram or litre to save a euro or two.

How can I make my own compost accelerator?

If you don't want to buy a compost accelerator, but would rather make it yourself, you have several options.


A homemade compost accelerator is also an excellent way to speed up the decomposition process. (Image source: Ben Kerckx / Pixabay)

One option would be to make a compost accelerator from yeast. This organic compost accelerator ensures warmer temperatures and thus faster rotting of the compost. This variant is most likely to be worthwhile when the ambient temperatures are mild.

You need:

  • Yeast (1 cube)
  • Sugar (500 grams - 1 kilogram)
  • lukewarm water (about 10 litres)
  • a watering can

The yeast must be dissolved in some lukewarm water before adding the sugar. The concentrate is diluted with the remaining water and poured into a watering can. After about two hours of resting, you can finally pour the finished compost accelerator over the compost.

Compost accelerator from a plant mixture

Another way to make an accelerator on your own is to use a specific mixture of different plants.

You will need:

  • Nettles
  • Valerian
  • Comfrey or fern fronds
  • Water

You need to mix these plants together and then add some water. Let the mixture stand for a few hours so that the fermentation process can take place. Then add more water to the mixture in a ratio of 1:10 and finally add this mixture to the compost.


The process of composting takes time. If you want to get valuable compost faster, consider a compost accelerator. This can save you several months of composting time and allow you to take control of your compost pile. This way you will have valuable and nutritious fertiliser for your favourite plants whenever you need it.

We hope that this article will help you with your purchase decision and that you will find the right compost accelerator for you very soon.

Picture source: 123rf / 111940410_m

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