In order for the plants in the house, on the balcony and in the garden to thrive as best as possible, they need light, warmth, water and also a suitable substrate that contains important nutrients. When it comes to earth, however, the question arises as to which is the right one. Should you choose a potting soil or rather a potting soil? And where is the difference anyway?
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benchmarks or standards
One would think that there are binding guidelines or even standards for the designation of soil mixtures. But that’s not the case. The manufacturers alone decide how to declare their substrates. Because of this, labeling is often a bit confusing and doesn’t necessarily mean that flowers grow better in potting soil than potting soil. The ingredients of the earth are therefore much more important. Despite this problem, the terms can be defined more precisely.
Both potting soil and potting soil are designed to provide plants with a good foundation for healthy growth. Since the basic requirements for the soil have to be met for almost all plant species, the most important ingredients of potting and potting soil are similar. However, the amounts of the individual components can vary greatly. The ingredients in soil include:
- organic components: mostly humus or peat
- additionally often compost
- mineral components: sand, clay or silt
- provide better structure
- Lime (to adjust pH)
- Additives (such as algae, coconut or wood fibers)
purpose of use
In general, it can be said that both potting soil and potting soil meet the basic needs of almost all plants. In most cases, however, potting soil is designed for outdoor planting, potting soil for growing in pots. Due to the difficult growth conditions in the pot, higher demands are placed on the substrate. That is why it differs from normal potting soil in a number of ways.
In most cases, potting soil is not used as the only substrate, but when planting in a bed or in the garden. They should help to improve the soil conditions and to optimize their properties. Universal potting soils are not tailored to a specific plant species. That is why there is a range of special soils for roses, vegetables or tomatoes. Normal potting soil is usually suitable for plants in the garden, in raised beds or in a greenhouse . These include, for example:
- shrubs (trees, shrubs)
- Perennials in the garden bed
All flowers and plants that are not cultivated outdoors but in pots have completely different requirements regarding the substrate. Due to the limited availability of space and soil, the demands on the substrate in terms of certain properties such as storage and drainage of irrigation water are particularly high.
- indoor plants
- Flowers in balcony boxes
- Plants in pots on the balcony or terrace
- Perennials and flowers in beds and borders
- moderately fertilized potting soil: universally applicable
Even if the composition of the two substrates is very similar, the difference lies in the details. This comes from the different areas of application for the earths. Since potted plants usually have different conditions than their relatives outdoors, the composition of the substrate usually differs from potting soil. In general, however, it can be said that a moderately fertilized potting soil can be used for almost all plants, regardless of whether it is a pot plant, rose or an ornamental shrub.
Peat has ideal properties for high-quality potting soil. Above all, its enormous water storage capacity makes it popular for growing media. Potting soil differs from potting soil by its high proportion of 50 to 90% peat. Together with nutrients and additives such as clay, they create optimal substrates. The pH can easily be increased to the desired value with lime.
- Peat has a major impact on the pH of the substrate
- ensures good water retention
- loosens the soil
One of the most important ingredients for good substrates is humus. It is responsible for the characteristic brown coloring of the soil and not only determines the soil’s water, heat and air balance, but also has a buffer and filter function. Humus is therefore a decisive factor for the fertility of the soil. As a rule, potting soil has a significantly higher proportion of humus than potting soil. An exception is peat-free potting soil. Since the peat is not that easy to replace, a mixture of different components is used to guarantee similar properties:
- green compost
- wood fibers
- Coconut fiber
3. Water storage capacity
Ideally, potting soil contains certain ingredients that can store more moisture and nutrients in a limited space. Outdoor plants, which can spread their roots freely in the soil, usually do not need these ingredients, which is why they are only present in a few potting soils.
- Coconut fiber
While a potting soil uses the stability of the natural garden soil, a potting soil must be structurally stable on its own. The substrate must not sag and compact over time so that enough air can reach the roots and waterlogging does not occur. For this reason, unlike potting soil, potting soil usually contains various components or additives that ensure a better and more stable structure.
- Coconut phases
5. Nutrient Stock
Both commercially available potting soil and potting soil are mixed with fertilizer, which supplies the plants with vital nutrients in the first few weeks. Only special soils such as seed or cultivation soil have a significantly reduced nutrient content.
- Potting soil: little nitrogen, phosphate and sulfur, but more potassium
- Potting soil: more nitrogen, phosphate and sulfur, but less potassium
The addition of other substances changes the physical and chemical properties of the earth. These additives are primarily used to improve water drainage when watering, so that waterlogging and root rot do not occur. In contrast to a potting soil, a good potting soil usually contains a mixture of:
- quartz sand
- clay beads
Almost all soils, regardless of whether they are potting soil or potting soil, consist largely of peat and compost or humus. However, they often differ in their nutrient content, structure and permeability as well as the pH value. In practice, however, unlike potting soil, potting soil can be used universally. However, the very special composition that you will find on the packaging of a high-quality product is always decisive.