Vermiculite Soil (Growing Medium)

Vermiculite soil or vermiculite substrate is an absorbent, lightweight soil amendment that is made of mica minerals.

It is prized for its ability to retain water, which makes it extremely popular in terrariums and gardening.

As a result, it is often used in gardening and horticulture in order to cultivate stronger and healthier plants.

This article will discuss the various uses and benefits of vermiculite and how it can be beneficial to your terrarium. 

Quick Stats:
Scientific Name Vermiculite
Botanical Name Vermiculite Soil
Common Names Expanded Vermiculite
Origin Open-Pits; mined from mica ore
Color Gray to golden brown
PH Impact Neutral
Elemental Type Extracted Mineral

What Is Vermiculite Soil?

Vermiculite soil is an inert, volcanic material that is derived from mica ore.

It originates from the hydration of the mineral mica, which causes the mica to expand and form tiny, accordion-like sheets.

This expansion creates a substance that is light, absorbent, and has a high cation exchange capacity, making it ideal for terrarium use. 

Vermiculite Soil For Terrariums Info Card

Vermiculite Soil Facts

Vermiculite soil is a non-toxic material that is safe to use in all vivariums.

It is one of the most versatile soil amendments available, as it can be used to improve fertility and soil structure, retain water, and improve aeration.

Vermiculite is available in various grades, including coarse, medium, and fine. 


Vermiculite looks like small, flat pieces of reddish-brown material.

It is often compared to a crystal-like substance or sheet because of its accordion-like shape.

This soil amendment is light and fluffy, making it easy to amend and mix into a variety of potting mixes.

It is absorbent, which allows it to hold extra water for plants to feed on. 


Vermiculite is mined in several countries, including Russia, Australia, Brazil, Uganda, and the USA.

Open-pit or open-cast mining is the method used to extract vermiculite from the earth.

This is because the minerals are located close to the surface and so tunneling is not required.

It is a simple process to extract minerals from the earth.

No complex tunneling is necessary due to the minerals being located close to the surface.

Environmental Influence

Vermiculite soil is typically acid neutral with a pH of 7.0.

It has a high cation exchange capacity, which means it can help retain nutrients for use by plants.

This can help them to grow strong and healthy roots. 

Vivarium Type

Vermiculite soil is ideal for use in a variety of enclosures.

It can be used as a standalone substrate porous medium or used as a soil amendment.

It can also be used to help aerate existing soil in order to retain water and provide drainage.

Here is a recommended list of vivarium types this soil additive is commonly used:

  • Paludariums – Half aquatic/ half terrain-based enclosure.
  • Terrariums – Fully terrain-based enclosures with little to no aquatic features.

Vivarium Usage

Vermiculite soil can be used as a porous medium in most vivariums.

It can be used to create an ideal environment for plants, as it helps to gently aerate the soil and allows water to penetrate it.

It also helps to retain water, which is especially important during drier periods.

Vermiculite can help reduce evaporation, which helps keep terrariums at the optimal humidity level. 


Vermiculite soil has a number of advantages when it comes to terrariums and paludariums.

It is lightweight, which makes it easy to amend and manipulate.

This soil additive helps to retain water, which is especially important for plants that don’t like to dry out.

It is also non-toxic and is therefore safe to use around animals and people. 


The main disadvantage of vermiculite soil is that it is not very nutrient-rich.

This means that it will need to be amended with fertilizers or compost in order to provide the necessary nutrients for plants.

In addition, vermiculite can retain too much water if not used in moderation, which can lead to root rot and plant death. 

Buy Vermiculite Soil

When buying vermiculite soil, be sure to look for a reputable brand that is known for its quality and consistency.

Many companies offer vermiculite in various weights and grades, so be sure to select the one that best suits your preference.

Click the image below to find out more about the current price and other relative info:

Vermiculite Soil Preparation & Tips

Vermiculite soil can be easily added to existing potting mixes or soils.

It is fairly light and easy to mix, so it doesn’t require much effort.

It is essential to amend vermiculite with fertilizers or compost in order to provide the necessary nutrients for plants.

If you plan to use this soil additive alone, it is vital to monitor the water intake carefully to avoid over-watering. 

Vermiculite Soil Substitutes

There are a number of other soil amendments that can be used in terrariums as a substitute for vermiculite.

Peat moss, for example, is a popular choice as it is highly absorbent and can help to retain water.

Coconut coir is also an excellent choice, as it is lightweight and easy to work with.

It is also a great source of nutrients and helps to improve the structure of the soil. 

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Vermiculite soil is an excellent choice for terrariums and similar vivariums.

It is featherlight and easy to amend and helps to retain water.

Remember to combine vermiculite with fertilizers or compost, as it is not very nutrient-rich.

It is also important not to over-water terrariums, as too much water can lead to root rot and plant death.

Frequently Asked Questions

Yes, adding vermiculite to your soil can improve soil structure and aeration, enhancing the overall health of your plants. It can also improve drainage, help retain moisture, and aid in promoting beneficial microbial activity. Additionally, it can provide essential trace minerals to your soil, helping to maximize the health, growth, and development of your plants.

The major disadvantage of vermiculite is that it can be highly absorbent of moisture, which can create issues of mold and mildew growth if it is not dried out quickly.

Additionally, it can be difficult to keep the vermiculite contained in larger gardening applications, as it is known to scatter easily. Finally, vermiculite can be difficult to reposition, as it tends to break apart easily.

Both perlite and vermiculite have advantages when used in gardening. However, perlite tends to be more lightweight and helps to retain moisture, while vermiculite is heavier and helps loosen the soil. Therefore, the best choice depends on the type of soil and the desired result.

  • African Violet
  • Baby’s Breath
  • Begonia
  • Bluebell
  • Carnation
  • Geranium
  • Hydrangea
  • Ivy
  • Marigold
  • Nasturtium
  • Pansy
  • Petunia
  • Poppy
  • Snapdragon
  • Sunflower
  • Sweet Pea

Vermiculite can last many years in the soil and can be used as an effective soil amendment for many years. This natural mineral compound is lightweight and can help promote soil aeration, improve the soil‘s ability to hold water, and enhance nutrient absorption, making it an excellent soil amendment for longterm use.

No, you should not add too much vermiculite to your soil due to the likelihood of nutrient deficiencies and soil compaction. Vermiculite should be added in moderation, typically in a 2:1 sandtovermiculite ratio.

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