Everyone knows the typical orchid substrate made of large pieces of bark, which is ideal for cultivating the exotic beauties. It stores water, which prevents the moisture-loving plant from drying out, and its coarse texture guarantees enough air circulation for the aerial roots. In addition, it is loose and does not prevent the roots, which are quite weak, from growing. And although this type of substrate is the most common, it is far from the only one that is suitable. Below we will list which soil is suitable for orchids as an alternative or as an addition.
The ideal substrate has these properties
In order for orchid substrate to be really optimal for these special plants, it must:
- can store adequate amounts of moisture
- be able to absorb nutrients and release them to the plant
- Guarantee air circulation thanks to its loose consistency to enable healthy oxygen exchange
- be loose enough for the roots to grow through, as they cannot penetrate hard substrate
Conventional potting soil is suitable, but only as an admixture or in combination with coarse sand (see below).
Use coconut fiber as an orchid substrate
The name already reveals what this is about. The fibers of the coconuts are chopped up and then resemble normal potting soil with the subtle difference that, despite the finer consistency, the water can drain off wonderfully and the air can circulate. At the same time, its denser texture ensures the right stability for the plant more quickly, while the nutrients promote healthy and strong roots. Coconut fiber as soil for orchids is also able to store moisture - but nottomuch.
Instead of soil for orchids: hydroculture with clay granules or expanded clay
So-called hydroponics is becoming increasingly popular with orchid owners because it always provides the plants with the right amount of moisture and since you should definitely use a water level indicator, you always know exactly when it is time for new watering. Hydroculture works best entirelywithout substrate and in glass. However, many people choose to place the orchids in clay granules as an alternative, as this substrate offers more support and stability.
Charcoal as a substrate for epiphytic plants
charcoal –Not to be confused with hard coal and definitely not grilled!– is ideal for adding to other orchid substrates, but not as a sole substrate replacement as it is unable to retain moisture. But it has other valuable properties. On the one hand, it neutralizes odors, which is undoubtedly very useful for houseplants. On the other hand, the material has a pH-balancing effect, which prevents root burns, as well as antibacterial properties and has a healing effect as it absorbs pollutants.
In countries with very high humidity, charcoal is also used exclusively as soil for orchids, precisely because it does not retain additional moisture, which could quickly lead to root rot in these regions.
Which soil for orchids – Crushed cocoa shells
The shells are a waste product that is created during the production of chocolate and are therefore a purely natural product. A particularly important advantage is that the nutrients it contains are gradually released over the course of several years, as the material only decomposes very slowly. This is also the reason why people like to fertilize with it. Good air circulation is also guaranteed as it is a coarse substrate. Perfect for mixing into the soil for orchids.
Crushed bark as an orchid substrate
This is exactly the substrate you know from orchids. Bark is crushed and used in more or less large pieces as soil for orchids. The bark of pine and pine trees, but also eucalyptus, is ideal for this and can usually be found in stores without any problems. Not only do they have the wonderful ability to store moisture, but they also acidify a little when they decompose, which orchids simply love. They also keep the temperature fairly constant. A small disadvantage compared to cocoa shells is that the rind decomposes more quickly and needs to be replaced. But this is usually only necessary every 2-3 years.
Danger:Bark mulch is not suitable for orchids!
Water-storing peat moss (spaghnum)
The material from New Zealand is dried and pressed, while the European version is sold fresh and alive. However, both have the property of being able to absorb and store a lot of moisture. And that's what makes it so popular for moisture-loving orchids. It serves as an additive to the orchid substrate, which is spread over the substrate surface, but must be replaced with fresh annually. It also allows oxygen exchange perfectly.
Mix perlite into the orchid substrate
Some people swear by small amounts of perlite as an addition to the substrate, others like it less because it sinks quickly when watered and floats up when submerged. You simply have to test whether it is suitable for you. However, the fine volcanic rock is ideally able to store water and, due to its quite airy structure (it has plenty of pores), also reduces the weight of the overall substrate.
Mix soil for orchids with gravel or sand
Subterranean orchids, i.e. those in potting soil or other denser substrate, can be provided with coarse sand to increase or guarantee air circulation. This also prevents waterlogging as water permeability is increased. It is important that you only use quartz salt as, unlike other types, it does not release any salts. Limescale is not a problem either.
Gravel is also suitable as an additive to avoid waterlogging, i.e. as drainage. River gravel or quartz gravel is ideal. This type of drainage and substrate is also very practical if your pots tend to fall over. The stones make the vessel more stable. Theoretically, the plant could also grow entirely in gravel, but that would greatly increase the weight of the container, which is why pebbles are only used for the soil.
