It's the same with young plants as with children: they need a lot of care and attention so that a seed or a small cutting can grow into a large and healthy plant. Special potting soil supports the little plants on their way there.

You can also mix potting soil yourself

Table of Contents

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  1. the essentials in brief
  2. Why use potting soil?
  3. Mix the potting soil yourself
  4. Recommended growing soil
  5. frequently asked Questions

    6. the essentials in brief

    • Potting soil is loose, fine and germ-free - optimal conditions for a young plant
    • Cultivation soil and seed soil are synonyms for germ-free substrate with an optimal combination of nutrients for young plants
    • Potting soil can be mixed with proportions of: compost or bark humus, coconut fibers or wood fibers, sand or gravel or perlite

    Why should you use potting soil at all?

    Experienced gardeners swear by potting soil - and with good reason. This specially mixed soil for sowing and growing young plants contains more humus than normal garden soil, which ensures a fine and crumbly structure. In addition, the proportion of clay in such special soils is very low, which is beneficial for the development of the tender roots. Instead, potting soil often contains sand or other mineral additives to make it looser and more airy.

    In addition, at least ready-made potting soil is germ-free, i.e. it does not contain any germs such as fungal spores or bacteria, but also no pests or weed seeds. This freedom from germs is important so that the young plants, which are still tender and susceptible to diseases, remain healthy. Typically, potting soil is also quite low in nutrients, which has a positive effect on root development and thus on the later resistance of the plant. Only when the little plant is a bit bigger and has already developed a few leaves should you transplant it to more nutrient-rich soil.

    What is the difference between potting soil and potting soil?

    Cultivation soil and potting soil do not differ very much in their special composition, but commercial potting soil is often pre-fertilized and therefore quite rich in nutrients and salts. However, nutrient-rich soil is not suitable for plant cultivation, because the roots that are still growing cannot use this surplus at all, and the mineral salts are also harmful. In addition, seedlings and cuttings grown in nutrient-poor soil develop stronger roots because they had to search for nutrients more intensively.

    Sowing soil or growing soil? What is better?

    Sowing soil and growing soil is the same

    There is no difference between seed soil and potting soil. Instead, both terms describe a special soil that can be used both for sowing and for plant propagation via cuttings. Incidentally, herbal soil is also suitable for this purpose, as it is often rather low in nutrients and has a loose structure. For this reason, many dealers also sell these special substrates under the designation "seed and herb soil" or "cultivation and herb soil".

    Mix the potting soil yourself - this is how it works

    If you look for ways to mix potting soil yourself, the information received can be overwhelming - especially since every gardener insists on his own mixture and production and some other recipes do not apply or even warn against them. Some have had good experiences with a compost-based potting soil, while others advise against it. In principle, however, any mixture is suitable as long as it meets the following basic requirements:

    • loose, fine-crumbly composition
    • good water storage, but permeable and not clumping
    • low in nutrients
    • germ-free and free from weed seeds

    What's in potting soil?

    "Peat is mostly carbon, which oxidizes as it breaks down, releasing large amounts of carbon dioxide into the atmosphere."

    Commercial potting soil contains - like many other substrates - mainly peat. However, we advise against this component for environmental reasons, because peat extraction irretrievably destroys moorland. These not only provide a home for numerous rare animal and plant species, but also serve as an important storage medium for the greenhouse gas CO2. Fortunately, however, there are many other raw materials that can be used to create your own home-mixed potting soil.

    • compost: Compost, preferably from your own garden, is a very good substitute for peat for many mixtures - after all, potting soil should not be completely nutrient-free, but only low in nutrients. Leaf or green cuttings compost is particularly suitable.
    • bark humus: Bark humus is created by composting spruce or pine bark, is wonderfully water-permeable and yet stable.
    • coconut fibers: These often come in blocks or as source tablets, so you don't have to lug heavy when shopping. Coconut fibers are a good substitute for peat, but they are questionable for ecological reasons: After all, they first have to be brought here from distant regions.
    • wood fibers: On the other hand, wood fibers are ecologically better and provide similar advantages to exotic coconut fibres. Be sure to get some made of untreated wood.
    • sand or gravel: Sand or gravel should not be missing in any seed soil, because the mineral material ensures a loose and well-drained substrate. In addition, it contains no nutrients. But be careful: Never use play sand, because this is too fine and would make the seed soil hard as concrete after watering.
    • perlite: Instead of sand, you can also use volcanic perlite, which is usually mixed with lime.

    Different compositions for different plants

    There are numerous recipes for self-mixed potting soil, which can and must all have different ingredients: After all, not all ingredients are suitable for all plants. For example, while vegetable plants grow best in a humus-rich substrate, cacti and other succulents need a more mineral one. So don't start mixing right away, but choose the starting materials according to the needs of the plants to be grown in them. Here we have put together a few examples for you:

    Appropriate species ingredients and composition
    heavy feeder many vegetables such as peppers, tomatoes, courgettes, aubergines and carrots, but also strawberries and geraniums Garden soil, bark humus and sand 10% each, compost soil 30%, wood or coconut fibers 40%
    medium eater Vegetables such as cucumbers, kohlrabi, squash and melons, salads and herbs, and flowers such as roses, dahlias and gloxinias Bark humus 15%, compost 20%, sand 15%, wood or coconut fiber 50%
    weak feeder some herbs such as parsley and garden cress as well as many flowers such as petunias, cosmea, primroses, begonias and azaleas cf. Mittelzehrer, only with garden soil instead of compost
    cacti and succulents many types of cacti (not all!) and succulents, e.g. B. Sempervivum Normal, fine-grained garden soil 40%, expanded clay (19.73€) (broken) 30%, perlite 20%, fine gravel 10%
    orchids all orchid species with the exception of terrestrial orchids Pine bark 80%, sphagnum moss 20%

    Add some charcoal ash, rock flour (€14.13) or algae lime (the latter only for lime-tolerant species!) to the respective mixtures to strengthen the plants' resistance to fungal diseases.

    This article clearly explains how to mix suitable growing soil for peppers and chili:

    youtube

    Mix and disinfect potting soil

    Once the required material has been selected and obtained, you can now start mixing. Be sure to use the correct mixing ratio as specified in the table. Now proceed as follows:

    1. Thoroughly clean all vessels and tools.
    2. Sift through the different ingredients.
    3. Gather out solid parts such as stones and root remains.
    4. Weigh the individual components.
    5. Now mix them carefully.
    6. Moisten the substrate.
    7. Disinfect the mixture in a preheated oven at 150°C for 45 minutes.

    Never leave the house while the soil is still in the oven: if it is too dry, it can start to burn.

    digression

    Determine suitability as growing soil by means of a "cress test".

    If you are not yet sure whether your self-mixed potting soil is really good, you can test it with normal watercress before using it for the first time. This is how it works: Sow cress seeds on a small sample of soil and wait: The seeds should germinate within three days and develop healthy, white roots after a week. If the cress grows as described, everything is fine and you can also use your seed soil for other plants. If not, the mixture would have to be optimized again.

    Buy potting soil - These varieties are recommended

    Depending on the plant, different types of soil are suitable

    Of course, bought ready-made soil also has its justification and has a number of advantages over self-mixed ones: This growing soil, if it is of high quality, is always ready for use and can be used straight from the bag. So you don't have to first get the various components, mix them in the right ratio and then disinfect them, you can get started right away. The market for various potting and special soils - which also includes potting soil - is gigantic. No wonder that consumers quickly lose track of things.

    That is why we have clearly presented the most popular branded soils for you in this table.

    Compo Sana Floragard Neudorff stretcher Plantop Euflor
    designation Cultivation and herbal soil Organic herb and seed soil NeudoHum seed and herb soil Organic seed and herb soil seed soil Organic seed and herb soil
    use Sowing, propagation, herbs Sowing, propagation, repotting, for herbs Sowing, propagation, herbs Sowing, propagation by cuttings Sowing, propagation of cuttings, pricking out Sowing, propagation of cuttings, pricking out
    ingredients contains peat and perlite 2 varieties: peat-reduced and peat-free, with compost and perlite peat free peat free contains peat, as well as clay and perlite contains peat and perlite
    additives Initial fertilization for six weeks coconut pulp seaweed meal - - organic natural fertilizer
    packaging 5L, 10L, 15L 5L, 10L, 20L, 40L 3L, 10L 10L, 20L 20L 15L, 40L
    price between 6 and 10 EUR between 5 and 12 EUR between 4 and 9 EUR between 4 and 6 euros between 5 to 6 EUR between 8 and 22 EUR

    However, it does not always have to be expensive branded soil, some hardware stores now have peat-free growing soil of good quality, sometimes in organic quality. Examples of recommended varieties are:

    market ingredients price
    Gardol seed and herb soil bauhaus peat free 20 L / approx. 5 EUR
    Organic seed and herb soil stretcher peat free 15 L / approx. 6 EUR
    FloraSelf Nature potting soil without peat Hornbach peat-free, with natural fertilizer and quartz sand 15 L / approx. 5 EUR

    tips

    On the other hand, very cheap seed and cultivation soil from the various discounters almost always contains peat. The only exceptions are soils based on coconut fibers, so-called coconut soil or source soil. Incidentally, a soil is only “peat-free” if this is explicitly stated on the packaging.

    frequently asked Questions

    What pH value should potting soil have?

    Commercially available seed or potting soil has a pH value between 5.5 and 7. If you mix it yourself, make sure that your soil has a neutral pH value, as most garden plants need this for healthy growth. Test the value with the help of a test stick, which you can get in the pharmacy or in the garden center. Neutralize substrate that is too acidic with some garden lime.(9.70€)

    What is expanded clay?

    Expanded clay is a mineral substrate, which - as the name suggests - is made of clay. Here, loamy clay is first expanded at high temperatures and then burned, which usually produces small balls. The material has a high water absorbency without causing waterlogging. For this reason, expanded clay - just like other clay granules - is a popular addition to many plant substrates.

    Can potting soil also be disinfected in the microwave?

    Yes, it even works very well and is faster than in the oven. However, you can only disinfect small amounts of soil at a time. And this is how it works: Spread part of the substrate thinly on a flat plate. Moisten it slightly because the germs and bacteria are not killed by the heat alone, but by the heated water. Then let the microwave run at the highest level for at least four minutes: bacterial pathogens are only neutralized after this time.

    Can you also use cat litter for self-mixed potting soil?

    As long as you use a purely mineral and non-clumping variety, cat litter is very suitable for plant species with low nutrient requirements. Cacti, for example, grow very well in it.

    What is pricking and when should you do it?

    When pricking out, seedlings that are too close together are planted farther apart so that they can develop properly. For most plant species, the best time to do this is when the seedling has developed the first true pair of leaves after the cotyledons.

    The seeds do not germinate despite the potting soil. What went wrong?

    There are various reasons for this: Seed often does not sprout if the germination conditions are not right and it is too cold or too warm. Many plants also need stratification, i. H. they must be kept cool for a few weeks. Not infrequently, however, the seed is simply too old and therefore no longer germinable, for example when using leftover seeds from last year or because the dealer sold bad seed. Also make sure that there are light and dark germs: Some types of plants need light to germinate and must therefore not be covered with soil, others not. Moisture is also very important: the potting soil must not dry out, otherwise the seeds will also lose their ability to germinate,

    The growing soil molds. Why?

    If the growing soil consists of organic starting materials, these can become mouldy. Mold often occurs when the substrate is too damp and, for example, the cultivation container has not been aired regularly.

    tips

    If the young plants are to be pricked out, i.e. isolated, you can add some horn meal to the potting soil and thus increase the nutrient content.

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Care tips