Home Plant guides What is Vermiculite and how can you use it with houseplants?

Vermiculite in a bucket

What is Vermiculite and how can you use it with houseplants?

Vermiculite are rectangular, super-light particles that are created by super-heating a hard mineral. By super-heating this mineral, it expands and creates air pockets, a little like heating up corn kernels to get popcorn. Vermiculite has the amazing ability of retaining a lot moisture, to help create the perfect growing environment for your moisture-loving houseplants.

Previously, we've looked at Leca as a soil-less growing medium, for those plants that like to dry out every once in a while. Vermiculite is the opposite and is perfect for those plants that love moisture. Vermiculite is also great for your next propagation project.

In this guide, we're going to look at these topics:

  1. What is Vermiculite?
  2. What are the advantages and disadvantages of Vermiculite?
  3. How you can use Vermiculite to grow your houseplants?

Let's get right into it, because I'm very excited to share this amazing growing medium with you!

What is Vermiculite?

In the introduction we've discovered that Vermiculite is a super-heated mineral. This super-heating process turns the mineral from a hard rock into very lightweight woodchip-like blocks. These blocks come in various sizes, from a few millimeters, to about 1.5 cm (0.5 inch). These sizes make quite a bit of difference when you're using them to grow your houseplants. The larger particles are great for using on their own to grow your houseplants, while the smaller particles are great to mix in with some soil.

People usually use Vermiculite for their fruit and vegetable gardens, because these plants love moist soil all the time. Vermiculite is sterile, which means it won't change the pH levels of your soil. This is important to know, because it means that you can add it to your soil without having to add an pH neutralizers. Convenient! It's great for fruits and vegetables, but can also be used for your houseplants.

What are the advantages and disadvantages of Vermiculite?

Three Vermiculite sizes Three Vermiculite sizes

Vermiculite is a great long-term solution to grow your moisture-loving plants. But when there are advantages, there must also be some disadvantages to using Vermiculite. Let's go through the pro's and cons and then you can decide if Vermiculite is something you'd like to give a try.

The advantages of Vermiculite

Vermiculite retains moisture a lot better than soil. Besides retaining water well, it also holds onto nutrients well and generally keeps its shape quite well. This helps to aerates the soil, as oxygen can freely pass between the particles. The combination of these 3 factors makes it a very welcoming place for growing moisture-loving plants, including fruits and vegetables.

Propagation

Vermiculite can be mixed in with soil, or be used on its own. It's a perfect growing medium when you're propagating your plants. It's a little like propagating your plants in water, but adding oxygen flow to the water. When you're propagating with only water, very little oxygen will reach the roots. Since the Vermiculite are solid particles, oxygen can easily pass between the individual pieces to reach the roots of your plant.

Light soil

When you mix Vermiculite with your soil, you're adding very lightweight pockets of air to your soil. When your soil is light while retaining moisture well, your plant can easily grow roots. Generally, when you have soil that's moist, it's quite heavy. This heavy soil makes it more difficult for your plant to grow roots more quickly. The light soil promotes growth and allows the roots to spread throughout the pot more quickly. Heavier soil also blocks more oxygen from reaching the roots, while the Vermiculite helps to improve the oxygen flow.

Fertilizing

Vermiculite, unlike most other hydroponic growing-mediums, is great at absorbing nutrients. Vermiculite helps your plants to absorb nutrients more quickly, which is great for promoting a lot of quick growth. Now you can see why fruit and vegetable growers regularly use this growing medium.

Long-term solution

Vermiculite is a sterile growing medium without any living organisms. The biggest benefit of this is that Vermiculite can't go bad. It's naturally resistant to fungi, mold, and other diseases. This makes it a perfect part of the soil for your moisture-loving plants. This type of moisture is usually a perfect place for fungi to grow. Vermiculite helps to prevent this.

The disadvantages of Vermiculite

Vermiculite is great, but it also has a major disadvantage. When you're using Vermiculite, it's very important to experiment to find the right proportions of Vermiculite to soil. If you add too much Vermiculite, it's quite easy to over water your plants. The water-retaining properties that are the huge benefit of Vermiculite, can quickly turn into it's downside. It holds onto moisture for a very long time and doesn't drain well by itself. This could cause root rot.

Because it's quite easy to over water your plant with it, I'll give you a soil mix in that helps to improve drainage and make this growing-medium your best friend.

How you can use Vermiculite to grow your houseplants?

Calathea Ornata growing in Vermiculite mix Calathea Ornata growing in Vermiculite mix

So you've decided to keep reading after seeing the biggest disadvantage and still think trying Vermiculite is worth a try? Great! In this section, I'll give you the soil mix proportions I've used for my Calathea Ornata, which is picky plant that loves moisture. This soil mixture brought it back from death and actually helps the plant thrive, without too much effort.

This fact makes me so excited to share this soil mixture with you, because if it helped me, it might help you too!

The Vermiculite soil mixture

A great mix of Vermiculite in soil, as we've already discussed in How to make your soil retain more water?, is:

  • 1/6 Vermiculite
  • 2/6 leca/perlite/sand
  • 3/6 (half) soil

This mixture gives you great moisture retention, but also makes sure the soil doesn't retain too much water. This soil mixture helps to get plenty of oxygen to your plant's roots, provide it with the moisture it loves, while also providing excellent drainage. I'm very excited about this soil mixture and I hope it helps you to take care of your moisture-loving plants too.

Conclusion

Vermiculite is a hydroponics growing-medium that is also very easy to mix with soil to help your moisture-loving plants thrive. Vermiculite is naturally resistant to fungi, mold, and other diseases and can absorb nutrients to feed your plant. It's only disadvantage, that I've experienced, is that it's very important to experiment with it to find the right proportions between it and soil. Vermiculite is a very versatile growing-medium and has already proven it's worth to me by saving my Calathea Ornata.

Thank you for reading this post! I hope it helps you to keep your plants healthy and beautiful! If you're looking for more guides on specific plants, you can always request a plant guide or donate a plant in order to get a guide for the plant you have trouble with.

Tags: vermiculite, soil, moisture, growing-medium

Posted on: Jun 6, 2021 Last updated on: Jul 26, 2021

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