Vermiculite Vs. Perlite | Knowing The Differences

Gardeners have to improve their soil each growing season to ensure that their harvest is bountiful. Each year, our plants deplete the soil of necessary nutrients, and we need to add some back. Many gardeners question the differences of vermiculite vs. perlite.


They are both used in a similar way, but they aren’t interchangeable, so it is important to understand the difference. Vermiculite and perlite are both used for composition and improving your soil, but they work in different ways. So, think about what your garden needs to help make the decision.



Vermiculite is an aluminum-iron magnesium silicate, similar to the appearance of mica. It is a spongy-like material, consisting of over 19 different micaceous minerals. Typically, it is golden or dark brown in color.

When used for agriculture purposes, it is heated to temperatures between 1472 and 2012 degrees Fahrenheit to make the particles expand, allowing it to absorb moisture as a potting medium. Amazingly, vermiculite can absorb three to four times its volume! Another reason that it is perfect for composition is that it attracts nutrients like potassium, calcium, phosphorus, and magnesium.

On the other hand, perlite is a glassy, volcanic rock, rich in silicon. Perlite reminds you of a pumice-like material, white in color. Sometimes, it looks like tiny balls of foam inside of your potting soil. To make it used as a potting medium, they crush the perlite and heat it up to 1472 degrees Fahrenheit so that it can expand the particles. Then, the microscopic bubbles inside of the perlite absorb and hold the water. However, perlite granules can also hold air.

Retaining Water

Capacity to Hold Water

You can use vermiculite and perlite to absorb water. However, because of its spongy-like material, vermiculite does hold the water better. It can absorb more than perlite. The problem with vermiculite is that it can hold too much water if you get a heavy rain or pour too much into a pot.

However, you could use perlite to absorb water in the soil. The surface area has little nooks that are perfect for collecting water. The benefit of using perlite is that it allows extra water to drain, improving soil aeration.

Overall, vermiculite is better at retaining water, with a high water holding capacity, whereas perlite has a medium rating. If you have a plant that wants moist soil at all times, go for the vermiculite.

Soil Aeration

Aerating Soil

Vermiculite and perlite can be used for soil aeration because they both have spaces that contain air. Roots can get oxygen through these spaces in the particles. If your purpose is to buy one for soil aeration, perlite is your best choice. It has the highest air porosity, whereas vermiculite has medium porosity.

When you go to purchase perlite, you will notice different grades – coarse, medium and fine. Coarse perlite has the best air-filled porosity, followed by medium and fine. Coarse granules have a rigid shape, allowing more space between each one. If you have a plant that requires a lot of drainage, opt for the perlite.

Using Them in the Garden

Organic Soil

Gardeners can use both in their garden to prevent soil compaction. Compacting the soil can lead to weak growth and a small harvest. Many gardeners use it to grow new plants and seedlings. They are perfect for indoor, container gardening. Some people use it for composting.

You also need to consider the soil pH; the right level is essential for many plants. Vermiculite and perlite have a neutral pH so that they won’t change your levels. However, they have different ways they buffer pH changes. Perlite has a small capacity for pH buffering, but vermiculite has a high rating. Perlite cannot hold plant nutrients as well as vermiculite. Also, using vermiculite adds potassium and magnesium to your soil, but perlite adds nothing to your soil mix.

For mushroom growers, vermiculite can be used to add moisture to the surface that they grow upon. You couldn’t use perlite for this purpose. However, you could use perlite to add humidity levels, perfect for growing seedlings. It allows evaporation off more surface area; a task vermiculite will fail.

Here’s a short video for you to know more about perlite & vermiculite.


Confusing vermiculite and perlite is easy. They are similar, but their purposes are necessary to distinguish. You should use vermiculite if you need to retain water, offer less aeration, and want to add potassium and magnesium to your soil. Vermiculite is ideal for plants that don’t want to dry out, ever.

If you need to hold some water, offer more aeration, and don’t want to alter your soil mix, perlite is the best choice for your garden. You can use it to dry out your soil and increase humidity.

It is important for you to understand the specific needs of your plants. Every plant has different requirements, and you can’t make the right choice without that knowledge. We hope that this information was helpful! If it was, make sure to share it!

About the Author Laura Bennett

Hello, I’m Laura Bennett. I love nature especially when it comes to flowers and different kinds of plants. I started a very small garden behind my house and I named it Humid Garden. So, I created this blog to provide aspiring and inspiring thoughts about gardening for gardeners and anyone who has the intention of keeping a garden.

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