How To Make Orchid Substrate Yourself

How To Make Orchid Substrate Yourself

Mixing your own orchid substrate is easier than you might think. The advantage: You know what’s in it and can adjust the mixture exactly to your orchid. I’ll tell you how to do it.


To mix your own orchid substrate*, you first need to know what different ingredients it can contain. Therefore, I will first introduce you to some of the common ingredients of orchid substrate:

Pine Bark


The classic and probably the thing you think of first when you hear orchid substrate is tree bark. That’s because this ingredient is unmistakably present in most purchased substrates. In most cases, it is pine bark*. It is available in different grain sizes from rather coarse (30 mm grain size) to very fine (6 mm grain size).

It is obtained from the bark of the pine tree (Pinus pinea) or the Monterey pine (Pinus radiata). While the former is mainly native to the Mediterranean region, the latter grows in the coastal regions of California and on a few Mexican islands. The best quality results when the bark is harvested from older trees at higher elevations.

Before it is used, pine bark is often lightly composted to break down tannins it contains. The reason you will find it in almost any orchid substrate is because it is suitable for most orchid species. It is also very stable and keeps its structure for up to five years. You can often buy it pre-fertilized.

Note: Bark mulch is also made from pine bark, but it is NOT suitable as a substrate for your orchids.

Sphagnum moss


Peat moss*, also called Sphagnum in technical language, is imported dried and pressed from New Zealand and sold here. When you unpack the moss and water it, it multiplies its volume. However, it is dead, so it does not turn green anymore.

Its peculiarity is that it can hold and store a large amount of water. This makes Sphagnum especially suitable for many cool-growing species and those that are tricky to grow. It is also used to root back bulbs or weakening orchids. It is important to repot your orchids in fresh moss once each year when growing in Sphagnum.

By the way, New Zealand sphagnum moss should not be confused with European sphagnum moss. The latter is finer and is often sold alive so that it turns green again after watering.

How To Make Orchid Substrate Yourself

Charcoal


In line with the soon to start barbecue season, we do not want to neglect charcoal* as a substrate addition. However, barbecue charcoal is unlikely to be suitable for your orchids.

The charcoal to be used as substrate for orchids must meet some quality standards. It must be granular, dust-free and come from hardwood trees such as hornbeam, beech or oak. Before you mix the charcoal into the substrate, you must rinse it once to remove adhering dust.

In the orchid substrate, charcoal increases the water permeability and at the same time binds harmful salts, for example from excess orchid fertilizer. Since young orchids in particular are more sensitive to waterlogging and too much salt on the roots, an admixture of up to 20% charcoal is recommended for their substrate.

Gravel


If you’ve been following me for a while, you know the saying: orchids don’t like wet feet. And a magic word against waterlogging in the substrate is called gravel*. Gravel ensures good drainage, i.e. water permeability, in the substrate. River or quartz gravel is used.

Incidentally, it also increases the weight of the substrate, so that the pot is more stable. This can be a trick with orchids, for example, which tend to grow to one side and thus run the risk of tipping over.

Sand


In addition to gravel, coarse sand* is also used in orchid substrates. It increases water permeability while maintaining a low water holding capacity. Therefore, it is often used for the cultivation of terrestrial orchids.

If you want to add sand, you should use quartz sand. It does not release any salts or lime to the rest of the substrate and thus to the plants.

Perlite


Perlite is a rock that is also called volcanic glass or obsidian. It is formed when lava cools very quickly. Its special feature: it has a very high pore volume, so it is extremely airy.

This is why perlite* is often mixed into orchid substrates as an additive, firstly to reduce the volume weight of the substrate and secondly to increase its water-holding capacity. For this, it is sufficient to mix about 10% perlite into the substrate for your orchid.

Expanded clay


Another addition to the orchid substrate can be expanded clay*. Expanded clay has the property of absorbing water and then slowly releasing it. This also increases the area for water evaporation. However, a disadvantage is that the clay also stores the salts from the water and fertilizer, promoting salinization.

In addition to the blended components mentioned above, there are several other additives you can use for your substrate depending on your orchid.

Mixing orchid substrate yourself – this is how it works


As with many things in orchid culture, it is the same with the right substrate: Ask one hundred orchid growers and get one hundred and one answers. Every grower swears by his own mixture.

In the following I will give you a few selected substrate recipes from which you can mix the substrate for your orchid yourself. You are free to try out other mixing ratios and to add or omit other additives as you wish. Just see how you get along with the mixture and how your orchid reacts to the newly mixed substrate.

A part is always referred to as an undefined unit of measure in the recipes. You can mix a small portion of substrate with the recipes or a whole bucket for several orchids.

It is important that the relation of the ingredients to each other is correct. For example, if you specify “five parts”, you take five cups full of bark and add to it one part, that is, one cup, perlite and another part, that is, another cup, Sphagnum.

Mixing orchid substrate for Phalaenopsis orchids yourself


Since the Phalaenopsis is by far the most common orchid on windowsills, I’ll start with a substrate recipe for it. For your Phalaenopsis orchid, you can try the following mix:

  • Five parts medium to coarse pine bark (depending on pot size).
  • One part perlite
  • One part Sphagnum
  • One part expanded clay
  • One part charcoal


Toss all ingredients together and then mix thoroughly until evenly distributed. Then you can repot your orchid into the newly mixed substrate using my step by step instructions.

Mixing orchid substrate for Vanda orchids yourself


The Vanda has very air-hungry roots. Therefore, it is often cultivated bare-root, i.e. without substrate. If you want to put them in substrate, this airy mixture is recommended:

  • Eight parts coarsest pine bark.
  • One part Sphagnum
  • One part charcoal


With the Vanda, as with other orchids with particularly air-hungry roots, it is important that the substrate is extremely permeable to air. Therefore, use the coarsest pine bark you can get, and make sure that you really only use one part Sphagnum to eight parts bark.

Mixing your own orchid substrate for Cymbidium orchids
The Cymbidium differs from other indoor orchids as far as substrate is concerned. Because it likes it already more in the direction of normal potting soil (although it is still far from growing in such). It needs:

  • Five parts coarse pine bark
  • Four parts peat
  • One part humus


A few scoops of blue corn as fertilizer


So if you’ve ever wondered about little blue balls in the substrate of your cymbidium, now you know what they are all about.

How To Make Orchid Substrate Yourself

Mix orchid substrate for Phragmipedium orchids yourself.
This lady’s slipper makes mixing your own orchid substrate very easy. For him you just take Sphagnum pure, without any admixtures or additives. And that’s it.

Mixing your own orchid substrate for orchids with fine roots
Perhaps you noticed when repotting that some orchids have rather fine roots. For them, a special substrate mixture also goes into the pot:

  • Four parts fine pine bark
  • One part Sphagnum
  • One part charcoal
  • One part perlite


Some orchid growers also recommend adding cork or dried beech leaves here.

Conclusion about mixing your own orchid substrate


As you can see, it is no great art to mix the substrate for your orchids yourself. You just have to know which ingredients you need and in which ratio you mix them for which orchid.

Good sources for the individual components are, by the way, the orchid dealers. But you can also find a lot of things in well-stocked specialty stores and at the usual online retailers.

It is important to pay attention to good quality when selecting substrate ingredients. Often it is also worthwhile to buy larger quantities and then mix the substrate for several orchids.

I wish you much success in experimenting. Feel free to report on your experiences mixing substrate in the comments. I am curious!

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