Mulching: definition, advantages & procedure
Many gardeners swear by mulch. But what exactly is mulching and what advantages does it bring? We’ll show you what it is all about and how to do it correctly.
Anyone involved in sustainable gardening or permaculture will certainly have heard of mulching. Mulching is attractive to all amateur gardeners because it can reduce maintenance work in the garden and promises a higher yield. Of course, mulching brings improvement in the garden only if it is done correctly. To help you successfully mulch in your garden, we have compiled everything you need to know about sustainable gardening practices in this article.
What is mulching?
Mulching is a time-honoured practice in the garden. The word “mulch” means something like “unrotted organic material”. Thus, a mulch layer is a layer of unrotted plant debris. How does mulching work? Mulching involves spreading material, such as bark mulch or lawn clippings, onto the ground in an unrotted state and leaving it there. Thus, the soil does not lie bare but is covered with a layer of mulch. This brings many benefits for the soil and the plant: proper mulching helps improve soil fertility and structure.
What are the advantages of mulching?
If mulching is done correctly, it can provide many benefits. These can be broadly divided into three areas: Protection, nutrient input and weed suppression.
The mulch layer can be considered a protective layer, as it protects the soil from the effects of weather. The organic material insulates the soil, cooling it in summer and warming it in winter. This can even extend the growing season for crops. In addition, the layer of organic material prevents the evaporation of water from the soil. This allows the soil to retain water longer and requires less watering. In addition, a layer of mulch prevents soil erosion because the soil does not lie there without protection but is protected from being washed away during heavy rain, for example. The mulch layer contributes to the nutrient input, as it consists of organic material that decays slowly. Industrious microorganisms transform the material and make the nutrients it contains available to the plants in this way. In this way, the mulch layer continuously releases nutrients to the plants over time and less fertiliser needs to be applied. In addition, mulch materials such as bark mulch can be used against weeds: The mulch suppresses unwanted weeds, as they do not manage to grow through the mulch layer. A final benefit of mulching is also that waste materials from the garden, such as leaves or lawn clippings, can be meaningfully recycled by becoming mulch material.
The advantages of mulching at a glance:
- Insulation layer cools in summer and warms in winter
- Less evaporation = less watering
- Prevents soil erosion
- Valuable nutrients for the plant = higher yields
- Suppression of weeds
- Garden waste can be be sensibly utilised
What are the disadvantages of mulching?
However, if mulching is not practised properly, it can bring not only advantages but even disadvantages. First of all, the choice of the appropriate mulch material is crucial with the ratio of carbon and nitrogen (C/N ratio) playing a decisive role. Some materials, such as straw, contain a lot of carbon but hardly any nitrogen. As a result, the microorganisms need more nutrients to decompose the straw than is ultimately made available to the plants. The microorganisms even consume additional nutrients, which the plant then lacks. This can be recognised by low growth and yellow leaves of the plant. It is therefore important that mulch materials with low nitrogen content are additionally supplied with fertiliser. Suitable fertilisers for this purpose include horn shavings or an organic fertiliser with a long-term effect that provides nutrients over a long period of time. This way you can ensure that your mulch material will not have a negative effect on the plant.
Further problems can arise if the mulch material is too wet. This causes increased mould growth and also increased slug infestation. Snails and mould simply feel very comfortable in humid environments. A final disadvantage of mulching is that once mulched, it is no longer possible to work the soil under the mulch layer, unless, of course, you remove the mulch.
What you should pay attention to when mulching:
- Incorrect mulch can remove nutrients from the plants (C/N ratio)
- Moist mulch favours mould growth and snail infestation
- No possibility to work the soil under the mulch
What material is suitable for mulching?
Many organic materials can be used for mulching. In general, you can use almost everything that is available in the garden at any given time and which is in abundance anyway.
Suitable materials for mulching at a glance:
- Bark mulch
- Wood chips
- Lawn clippings
Of course, not all mulch materials are equally suitable for all plants and uses. For a detailed overview of different types of mulch and a description of what they are suitable for, see our dedicated article.
How to proceed?
Basically any time is a good time to start mulching in your garden. However, spring is a good time, when you start working the soil in the garden anyway, or autumn, when a lot of organic material accumulates.
Before you can start mulching, you need to make some preparations. Carefully remove all weeds from the area where you want to mulch. After that, the soil should be well loosened. Next, fertiliser is incorporated into the soil. This is necessary to ensure that there is enough nitrogen in the soil and that the organic material from the mulch can actually be converted well. For this purpose, we recommend a fertiliser with a long-term effect such as our Plantura All Purpose Plant Food, which ensures the nitrogen supply of the soil over a long period of time. It also contains other important nutrients for your plants.
Once the soil is well-prepared, you can apply the mulch. How thick you make the mulch layer is up to you. The thicker the layer, the longer it takes for the organic material to decompose. Generally, mulch layers with a height of between 5 and 15 centimetres have proven successful. When spreading the mulch, be sure to leave enough distance from the stems and trunks of the plants. If the mulch is too close to it, mould and rot can form. After the hard work is done, you can sit back and let nature do its work – there’s not much left for you to do. Only occasionally do weeds make it through the mulch layer. These can then be plucked out and become mulch themselves by placing it (on dry days only) directly on top of the mulch layer.
Tip: With us, you will also learn how to proceed specifically when mulching a vegetable bed.
Step-by-step guide to mulching:
- Weed well before mulching
- Loosen the soil
- incorporate fertiliser with organic long-term effect into the soil
- Spread mulch
- Keep at a sufficient distance from plants
- Let nature take its course
- Periodically remove weeds that make it through the mulch layer and leave them on top of the mulch