What is vermiculite and what is it for

Vermiculite is widely used in plant growing, both individually and as an additive to the substrate. However, many people are genuinely puzzled by this substance – what good can these flakes of unknown origin do and why are they now so popular among flower growers?

What is vermiculite?

The origin of vermiculite is very natural: this mineral is formed in the earth’s crust and is environmentally friendly. High temperature treatment makes it loose and flakey, which is how it ends up on store shelves. As you can see, the production technology has only one step, but the useful qualities of vermiculite are countless.

Vermiculite does not decompose or decay under the action of microorganisms, and is not a favorable habitat for rodents and insects. It does not react chemically with acids and alkalis. In this case, the material is non-toxic, sterile and does not contain heavy metals. But the content of calcium, potassium, magnesium, aluminum, iron and silicon gives vermiculite the honorary title of biostimulator of growth.

However, vermiculite cannot be called just an effective fertilizer, as it is also an incredibly water-holding soil loosener. The ability of this mineral to hold a volume of water five times its own weight makes it possible to create an optimal microclimate for plant roots without weighing the soil and preventing its aeration. On the contrary, the soil with vermiculite does not caking and retains a loose structure. If you apply a solution of fertilizer, its useful substances will stay in the porous structure of the material for some time and will gradually pass to the plants without the risk of burning the roots.

Application of vermiculite

  • Rooting cuttings, germinating seeds. For this you can use vermiculite in its pure form, because fungi and microorganisms do not live in it. And the stock of nutrients will be quite enough for the first time.
  • In soil mixes to provide the necessary porosity, friability and normalization of moisture. There are no clear recommendations on the observance of proportions, everything depends on the needs of a particular plant and the initial data of the soil substrate. Vermiculite can make up to 50% of the resulting mixture. In this case, the use of expanded clay is not necessary.
  • In hydroponics, both in its pure form and as a component of
  • As drainage
  • Storage of bulb plants. Vermiculite maintains thermal balance and keeps gas exchange normal, providing protection against rotting, fungus development and other diseases.

What to replace vermiculite with?

Of course, a full-fledged alternative does not exist, but if in your city vermiculite is not sold, there is a way out.

Coarse sand prevents caking of the soil and keeps it breathable for a long time. However, do not forget that fine sand as a substitute for vermiculite is not suitable – on the contrary, it makes the soil even more dense.

Styrofoam and coconut fiber are less common options, but they are no worse than sand in their properties and durability.

The great advantage of these loosening agents is that they do not change the chemical composition of the soil and can be used for any plants without exception. On the other hand, they do not do any more good.

Sometimes fine expanded clay is used as a substitute for vermiculite. Unlike sand, Styrofoam and coconut, it is able to accumulate moisture and, if necessary, give it to the substrate without overwatering. For the vast majority of indoor plants expanded clay is needed as a bottom drainage.