Perlite vs Vermiculite: Which One Is The Best For Your Plants?

Let’s talk about perlite vs vermiculite! These two growing mediums are useful for gardeners as they can improve the quality of soil by improving aeration, providing excellent amendment for soil structure, and offering better drainage. Besides, they can also release water as the plants need. Thus, the soil will not get soggy and their roots will stay healthy without rotting.

However, many people still mistakenly assume perlite for vermiculate and vice versa. Despite featuring similar purposes for gardening, perlite and vermiculite have different characteristics and thus are intended for different kinds of plants. And for that reason, we would love to give you tips on how to use perlite vs vermiculite properly for plant growth.

We will also cover some different characteristics of these growing mediums, so you can add them for vegetables in a correct manner.

Let’s dive in!

Definition of Perlite and Vermiculite

Having similar names, many mistakenly think that perlite and vermiculite are the same natural occurring materials. Even though their functions for growing plants, retaining moisture, and improving aeration are closely related, they have different characteristics.

perlite vs vermiculite
Perlite and Vermiculite

Therefore, their applications are intended for various kinds of plants with certain features. Let us break down one by one!

1. What Is Perlite?

Perlite is made of natural volcanic obsidian heated in high temperatures until it pops like popcorn. Hence, people refer to perlite as volcanic popcorn. This lightweight, non man made product, has white color and porous characteristics that helps perlite to improve water drainage as the water can easily escape the perlite soil.

perlite
What Is Perlite?

For that reason, perlite is widely used for cactus soil or other plants that love arid conditions. As it can hold water but not drown the roots, Besides, this porous pumice-like material is beneficial for some gardening purposes, like seedlings, planting plants in hanging pots, and more.

In addition, perlite is ideal to maintain soil moisture and enhance aeration. Moreover, this inorganic material is also good for soil structure as it offers aeration and drainage improvement.

2. What Is Vermiculite?

Meanwhile, vermiculite is an inorganic material that occurs naturally as it is exposed to extremely high temperatures, just like perlite. Unlike perlite that has shapes like styrofoam granules or popcorn, vermiculite features hexagonal shapes that resemble pebbles.

This structure is made during the heating process. Furthermore, these vermiculite pebbles will be further processed into lightweight, sterile coarse, medium, and fine products before being sold in the market.

vermiculite
What Is Vermiculite?

Since vermiculite is non-toxic and inert material, it is safe to use for composting. So, you don’t need to worry that your compost will combust during the fermentation process. Moreover, it belongs to the spongy-like materials that will benefit your houseplants most as they mostly need constant soil moisture.

It has a spongy-like surface that makes vermiculite absorb water more than perlite does. You can also add this spongy material for raised beds that require better aeration and drainage. As it features neutral to alkaline pH, vermiculite will also be useful for neutralizing the acidic soil.

Importance of Choosing The Right Growing Medium

Like humans, plants need adequate nutrients to thrive and grow healthily. Hence, they need the right growing medium that will allow them to absorb nutrients, water, and other minerals essential for their growth. Besides, the best growing medium will provide aeration that offer better oxygen exposures to the roots. That way, your plant’s roots will develop properly and, perhaps, faster.

Furthermore, the right growing area also ensures good soil aeration that can let the roots breathe. They also have more space to grow widely and deeply. In addition, aeration is crucial to release excessive moisture that can inhibit oxygen absorption. If that happens, your plant’s roots will drown and eventually rot.

Having a proper growing medium is also important in terms of providing excellent nutrient retention. You can imagine if your plants grow on the medium that let the water escape too quickly. The nutrient will be flushed down while your plants do not have a chance to utilize them for their growth. Hence, it is extremely crucial to choose the right one to ensure healthy growth.

perlite vs vermiculite
Importance of Choosing The Right Growing Medium

There are two types of growing medium you can use for planting, the inorganic and organic ones. Some examples of the inorganic medium are vermiculite, perlite, sand, hydrogel, and more. Meanwhile, coco coir, peat moss, and rice hulls are those organic materials that are considered more environmentally friendly. They have diverse characteristics with different purposes for your plants.

You can choose one that suits your plant’s features best. For instance, perlite mix is for those neutral-loving plants who do not prefer damp soil constantly, like cacti and succulents.

Meanwhile, plants that prefer growing on the acidic soil will appreciate coco coir addition to the potting mix. This man made product is also better in improving soil structure.

How Perlite and Vermiculite Made?

While we are discussing perlite vs vermiculite, it won’t be complete without understanding how perlite and vermiculite are made. They both are naturally occurring products that are good for vermicomposting.

Do they have similar processes? Or maybe they are made out of the same materials? Well, that’s not the case! Let’s take a look at how these inorganic soil amendments are produced!

1. How Perlite Is Made?

Like its name, perlite is made of natural volcanic glasses from the volcanic eruption. The rapid cooling lava trapped the air inside this inorganic material before vaporizing and exploding into white, lightweight, pop-corn like shapes due to extreme heat.

How Perlite Is Made
How Perlite Is Made?

Due to this process, perlite has a porous characteristic that helps water to flow through the soil rather quickly while retaining moisture on the surface. Moreover, the heating also creates tiny bubbles that trap air in between, allowing better drainage of the perlite soil  for the pots. You can also add perlite in your soilless mix.

2. How Vermiculite Is Made?

Same like perlite, vermiculite is also a natural occurring material that is mined in several countries, including Australia, South Africa, and Brazil. The process to obtain vermiculite includes mining and exfoliating. The top layer of rocks containing vermiculite will be removed before drilled to create holes.

Next, the holes will be filled with explosive charges and detonated into vermiculite flakes. These flakes will further be sorted out before being exfoliated with high temperatures. From this point, vermiculite will be processed into fine, medium, or coarse products and sold in the market.

Though vermiculite is generally non-toxic, the vermiculite in insulation may contain vermiculite asbestos, the needle-like particles, that is harmful to humans.

Perlite vs Vermiculite

To clear the air, it’s better to understand the difference between perlite and vermiculite in terms of the physical properties and the uses of these inorganic soil amendments for vegetables and plants. That way, you can ensure these growing mediums will support the growth of your plants by improving the aeration, water retention, and nutrient absorption.

We also cover benefits and drawbacks of perlite vs vermiculite you must know before adding one to your corps. Let’s get started!

1. Comparison of Physical Properties

There are reasons why perlite vs vermiculite uses are different. One of which is their physical properties. Perlite has white color, popcorn-like shape, and porous characteristics, having great pores around this inorganic material. This feature also allows perlite to retain moisture on the surface while allowing the water to escape the soil pretty quick.

Comparison Of Physical Properties
Comparison Of Physical Properties

Furthermore, its capillary action can hold water 3-4 times more but not as much as vermiculite, making it becomes lightweight In addition, perlite also bears tiny bubbles to improve soil drainage.

On the other hand, vermiculite has white, yellowish, translucent colors whose shapes vary according to the products. You can find coarse, medium, or fine vermiculite in the market. This mineral has neutral pH of around 7.0-7.5 which makes vermiculite ideal to grow diverse kinds of plants.

Moreover, it can retain water just like perlite, but the sponge-like surface allows vermiculite to absorb more. Despite being a non-toxic material, you must be aware of the vermiculite particles. Vermiculite insulation contains vermiculite asbestos that has needle-like shapes. It can be dangerous if you contaminate your eyes and whenever you inhale these tiny particles.

2. Comparison of Benefits and Drawbacks

Even though perlite and vermiculite have tons of benefits, there must be drawbacks hidden behind the bar. If you want to know more about it, let’s peel it off one by one below!

Perlite

Just like other gardening products, perlite has many advantages and some disadvantages you need to consider before adding one to your pots. One of the perlite benefits is it can provide sterile growing media for seed-starting. It will decrease the risk of root rotting due to pathogenic contamination and diseases.

Perlite is also great to add in soilless mix as it contains essential minerals to support your plant growth. This non-toxic material also has neutral pH of about 7.0 to 7.5, a perfect addition to any perlite soil for vegetables.

However, perlite is a non-renewable material that is often a concern. In addition, its lightweight feature makes perlite floats when you water your plants. Sometimes, water can dry faster as it is made of amorphous volcanic material.

Vermiculite

Bearing many benefits for your plants, vermiculite is popular for absorbing water better than perlite, thanks to its spongy structure.

But don’t worry! It will release water based on what the plants need, maintaining soil moisture for an extended period. So, it won’t overwhelm the roots with too much supply. Moreover, its platy structure allows better nutrient absorption. Similar to perlite, vermiculite is sterile and also has a neutral to a bit alkaline pH of 7.0-75. Thus, it is great to start seedlings and grow various crops.

Comparison of Benefits and Drawbacks
Comparison of Benefits and Drawbacks

Nonetheless, vermiculite can sometimes hold water too much, resulting in root rot as it is drowned in the water. This can lead to lack of oxygen which later choke the roots for rotting and make them withered before dying. Furthermore, this inorganic material also contains carbonate that may boost the alkaline reactions.

Consequently, the root pH will rise and stress them. Just like perlite, vermiculite is lightweight which will easily be blown away by the wind or float when you add water to the plants. In addition, horticultural vermiculite or vermiculite mix is not widely available in the gardening store.

3. Which To Use In Different Situations

Knowing that perlite features porous characteristics, it will benefit your plants especially those who need drainage aids. Such plants, like succulents and cacti, do not like constant moisture that will pose risks of root rot. At this point, you can offer perlite to the compost which will later be added to the plant’s pots.

This material will retain air in the compost, ensuring your plants have adequate moisture without overwhelming the roots with water. In addition, you can also add perlite in the germination process, particularly for seeds that need light to grow. It is because perlite has pores that let the sun or artificial light pass through the particles. 

Which To Use Perlite or Vermiculite In Different Situations
Which To Use Perlite or Vermiculite In Different Situations?

On the flip side, vermiculite mix is the best gardening product for those moisture-loving plants, like pothos, philodendron, or ferns. The spongy-like texture allows better water absorption of vermiculite; thus, you can expect excellent water retention. Having such a feature, vermiculite will benefit seeds that love to soak in the damp growing medium to germinate.

You can try introducing vermiculite to your houseplants, like maidenhair ferns or peace lily by adding the material with your compost. Use a 50:50 ratio to get the balance formula. Nonetheless, it will be wise not to overwater your plants growing on the vermiculite as it can hold up too much water.

As an additional information, perlite and vermiculite are both excellent for vermicomposting. Perlite offers to the vermicompost to aid better oxygen, nutrient, and water flow to the plant roots. Meanwhile, vermiculite can improve worm digestion for composting.

4. How Long Does Perlite and Vermiculite Last?

Both perlite and vermiculite do not break down or decompose in your garden soils. They are made of rock and, thus, do not have expiration dates like other organic materials, such as coco coir, peat moss, or rockwool. For that reason, they can forever nourish your soil.

Nevertheless, these inorganic materials can get contaminated by asbestos. It is a heat-resistant silicate with tiny particles that can be released into the air. The contaminated materials can impair the root growth of your plants. So, make sure you keep perlite and vermiculite following the producers guide.

How To Use Perlite and Vermiculite?

Using horticultural vermiculite and perlite is actually not tricky. Some gardeners simply mix them with other growing mediums while the rest prefer to use them for seedlings on their own

Below, we have summed up the best way to use and mix both materials with your garden soil and growing medium. Check them out!

1. Mixing Ratios with Soil or Other Growing Mediums

As we mentioned before, perlite and vermiculite are great for seed-starting. If you are interested to try making potting mix with perlite or vermiculite, you can check our curated recipe below:

  • 3 parts of peat moss.
  • 3 parts of coconut coir (the prepared one: bricks, pith, chips).
  • 3 parts of worm castings for the additional nutrients.
  • 1 part of perlite.
  • Water (rain or distilled water is the best).

You can also make one for outdoor planting with 1 layer of topsoil, 1 part of perlite, and 1 part of compost. It will be better to create your own compost since you know what materials you add to the compost bin.

In case you want to use both perlite and vermiculite to make a soilless potting mix, you can try our favorite formula:

  • 1 part of vermiculite.
  • 1 part of perlite.
  • Up to 6 parts of sphagnum peat moss.

2. Tips for Using Perlite and Vermiculite Effectively

The best tips for using perlite and vermiculite is when you know when to use both. Vermiculite holds water way better than perlite.

In this case, you can add more vermiculite to the potting mix for moisture-loving plants. The same goes for the perlite if you want to grow arid and desert plants where they do not need much water to thrive.

perlite vs vermiculite
Soil Mixed for Planting

You must also know the purpose of adding these materials to your potting mixes. For example, if you want to germinate your seeds indoors, meaning you must keep it moist. And so, you will need vermiculite to the rescue.

On the other hand, perlite is beneficial for those seeds who require light exposure as this material has great porosity which allows light to come through the tiny holes.

Best Products for Perlite and Vermiculite

If you are a beginner in trying perlite and vermiculite, we have scoured the web to help you find the best products you can use for your crops and plants. They are relatively affordable and widely available in the market.

Check them out below!

1. Espoma PR8 Organic Perlite

Espoma PR8 Organic Perlite
Espoma PR8 Organic Perlite

When it comes to reducing soil compactness, look no further than Espoma PR8 Organic Perlite. This product will help your heavy soil to loose, promoting better aeration and thus allow your plant’s roots to breathe.

By improving the soil quality, the roots can develop properly and you will have healthy crops to harvest later! Adding this organic perlite also prevents soil compaction for later use. Grab one at Walmart for around $20.21!

2. Hoffman 16504 Horticultural Perlite

perlite vs vermiculite
Hoffman 16504 Horticultural Perlite

Perlite is not only useful for improving your garden soil, but it is also beneficial to promote horticultural growth. If you want to add this growing media to your field, we highly recommend our favorite product Hoffman 16504 Horticultural Perlite. This product is lightweight, so you don’t have to worry about overwhelming your soil.

In addition, it will help you loosen the clay soil which eventually promotes better nutrient absorption. It also improves aeration and drainage. Thus, the roots can have better oxygen exposure to grow. Find one at Walmart for $27!

3. Casa de Amor Vermiculite

perlite vs vermiculite
Casa de Amor Vermiculite

Compared to perlite, vermiculite products for plants and hydroponics are pretty hard to find in the market. But luckily, we have found our most-liked product to boost your veggies and plant growth, the Casa de Amor Vermiculite for Gardening and Hydroponics. 

This gardening product is great to aerate the soil, promote soil microbe’s growth, and most importantly, suitable for both indoor and outdoor plants. You can get one for only $5.50!

Final Thoughts

Having similar names and purposes, many people think that perlite vs vermiculite are the same things. But in fact, they are pretty different. Perlite has excellent porosity while vermiculite is more spongy. Thus, gardeners tend to use perlite for their dry-loving plants and add vermiculite for plants that love moisture. Nonetheless, both of them offer adequate nutrients for your plants knowing they belong to mineral-based materials.

You can also add them alone in the soilless mix or mix perlite and vermiculite together with other growing mediums. Sadly, vermiculite is not widely available in the market nowadays. But, you can replace it with other organic material, like pine fines.


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FAQ (Frequently Asked Questions)

Can perlite cause root rot?

Since vermiculite holds more water than perlite, this non-toxic material will not make your plant’s roots rot. Its porous characteristic is useful for gardeners who wish to have a dry growing place, especially for arid plants.

Perlite offers easy water drainage, so you can introduce them for your succulent soil with no worries. Just make sure to add coarse if you want to have better aeration.

When should you add perlite?

In addition to adding the perlite for your potting soil, you can also add your growing medium for your raised beds in the fall. This method will protect the plant’s roots from waterlogging in the spring and winter. As for the shrubs and trees, you can introduce this non toxic material whenever you want to backfill the planting holes.

What is an alternative to vermiculite for packaging?

Besides being added to the potting soil for gardening, vermiculite is commonly used as packaging material, especially the inert. It can protect your product from impacts and shocks during shipping.

However, the vermiculite dust can be potentially harmful for the workers. Thus, it will be better to replace vermiculite with a sustainable alternative like biodegradable loose fill chips which function similarly to this inorganic material.

Can you substitute perlite for vermiculite?

Perlite and vermiculite are both excellent for plant growth. They are commonly added to the potting mix to retain moisture, enhance drainage, and improve nutrient retention. However, you cannot substitute perlite for vermiculate as their characteristics are different.

Perlite is porous pumice-like inorganic material that lets the water escape quickly through the porous, making it great for soil amendment. Meanwhile, vermiculite holds water more than perlite as it belongs to the sponge-like materials.

Hence, this spongy material has amazing nutrient retention that is good for seed starting.

Which is more expensive, perlite or vermiculite?

Talking about perlite vs vermiculite, people usually compare both growing mediums as to which one is the best for their plants. Both are mineral-based materials that have excellent water retention and release water as the plant needs. Regarding the price, perlite tends to be more expensive than vermiculite.

However, perlite has easy water drainage and soil aeration, providing a dry growing place for arid plants. That’s why perlite is a better option for cactus soil or succulent soil that needs a dry environment to boost the plant growth. 

Does perlite change the pH of soil?

Perlite belongs to the mineral-based materials which have neutral to alkaline pH around 7 to 7.5. Given the fact, adding perlite will not make your soil become acidic. Instead, it’s good for soil amendment because perlite can improve the quality of your soil by improving aeration and retaining moisture. 

Which plants benefit from perlite?

Perlite has excellent water retention but also improves drainage. Thus, your potting mix will drain pretty quickly. For that reason, arid plants, like succulents and cacti will benefit most from using perlite as their growing medium. You can add two parts of coarse and one part of perlite for the succulent soil to improve aeration. 

Generally, perlite mix contains compost that will let the water goes through as the perlite traps air within. Its porous characteristic also helps perlite to retain water well without getting it soggy.

Can you grow plants in 100% perlite?

Unlike coco coir that is not recommended as the mere growing medium for gardening, you can simply add 100% perlite. It is, in fact, beneficial for seed starting, especially the smaller ones. Not only will it retain water well and improve drainage, perlite can also improve aeration that allows better oxygen exposure to your plant’s roots.

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