Perlite vs vermiculite discussions are worth having so that you can know which product you should amend your soil with. Both perlite and vermiculite have essential uses when it comes to soil amendment, but they are simply not the same.

Perlite vs Vermiculite Which One is Best for Your Soil Plant America

Continue reading this guide to learn everything that you need to know about vermiculite versus perlite.

Quick Overview

Here is a quick table of comparison between these two substances.

Perlite Vermiculite
Composition Silicon-rich amorphous volcanic rock Silicate of aluminum, iron and magnesium
Appearance Looks like a pumice or white granules; resembles little plastic foam balls Looks like spongy, dark or golden brown flakes
Uses Drains water quickly and aerates the soil Absorbs water like a sponge; can retain nutrients such as potassium, magnesium, calcium and phosphorus

What’s the Difference Between Perlite and Vermiculite?

The main difference between perlite and vermiculite is that perlite drains water quickly while vermiculite absorbs water like a sponge. Another difference is vermiculite looks like dark or golden brown flakes while perlite looks similar to white granules or foam balls.

Here are the major differences between perlite and vermiculite in detail:

– Composition

Perlite is a silicon-rich amorphous volcanic rock, so it naturally occurs close to volcanic eruptions. The composition of perlite helps it to drain moisture quickly. Even though perlite has a large surface area (as it is very porous), it drains water quickly since water can pass through it with ease.

As for vermiculite, it is a silicate of aluminum, iron and magnesium. The composition of vermiculite helps it to absorb water just like a sponge. It quickly absorbs water but is not quick to drain water, which means that there could be moist vermiculite in your dry soil.

– Description and Appearance

When dry, vermiculite looks like flakes. It is spongy and can be dark or golden brown. Perlite is a material that is porous and looks like a pumice or white granules. Perlites resemble little plastic foam balls when you amend soil with it.

When you mix perlite and vermiculite together with soil, they give the soil a very beautiful appearance as it can have a mixture of brown, black and white specks according to the type of soil that you use.

– Uses

One of the major differences between vermiculite and perlite is in their applications. When should you use perlite? What about vermiculite? Here are their respective uses:

  • Water Drainage

If your soil is waterlogged or you simply want to increase the rate at which it drains water, you should amend it with perlite.

  • Moisture Retention

Does your soil get dry quickly? If you do not have enough time to always water your crops, you can simply amend the soil with vermiculite so that your plants will still have access to moisture even in dry soil. You should use vermiculite for soil moisture retention.

  • Aeration

Are your plants suffering from lack of oxygen? Do they look extremely weak under the sun? Amend the soil with perlite to increase the availability of oxygen in the soil. A waterlogged soil does not have enough oxygen and can kill you plants.

  • Soil Nutrient Amendment

A problem that gardeners often face is that their nutrients leach off quickly in loose soil. If your garden soil loses nutrients quickly, amend the soil with vermiculite so that nutrients such as potassium, magnesium, calcium and phosphorus can stay within the soil.

Even though the purpose of vermiculite is not specifically for soil nutrients, this is an added advantage.

  • Temperature

Due to the ability to increase the availability of air in your soil while retaining moisture, both perlite and vermiculite can help stabilize the soil temperature. Vermiculite is more effective, however, so you should amend your soil with vermiculite and water your plants with cool water.

  • Reduce the Weight of Soil

Do your plants suffer from suffocation? Is your garden pot or container too heavy to carry? You can reduce the soil weight by amending it with perlite.

Now that you know the differences between perlite and vermiculite, it is time to discuss them individually so that you can decide when to use either or both of them.

Perlite vs Vermiculite: Full Explanation

Both perlite and vermiculite have a lot of uses in soil amendment. They are either used to regulate soil moisture retention or the water drainage ability of the soil.

Many times, gardeners use both perlite and vermiculite to amend soil or make potting mix. Since they are used together a lot of the time, people feel that they can use perlite and vermiculite interchangeably.

Can you use perlite and vermiculite interchangeably? When should you use perlite or vermiculite? Let us discuss what perlite and vermiculite truly are.

– What Is Perlite?

Perlite is a lightweight, colorless and odorless substance with a pH of 6.6 to 7.5. It is rich in silicon as an amorphous volcanic rock. When people collect perlite particles to be used as plant substrates, they heat and crush them to expand the particles.

Perlite vs Vermiculite Comparison Guide Plant America

As the perlite particles expand, they hold the air which makes perlite a very good soil amendment product if you want to increase your soil drainage abilities. Take note that perlite particles can also hold moisture but it drains off quickly, leaving just the air.

Here are some uses of perlite.

  • Making Substrate Lightweight

Perlite is lightweight but occupies a lot of space. This means that when making potting mix or amending the soil, you can have a lot of product but still carry it with ease as it is not so heavy. This is important so that plant roots can easily spread in the substrate.

  • Increasing Soil Drainage Ability

Moisture drains quickly in substrate amended with perlite. If you live in a waterlogged area or you are growing crops that hate soggy soil, you should amend the soil with perlite.

  • Soil Aeration

Your plant roots will have more access to oxygen when you grow them in soil or potting mix that has perlite. The roots can collect oxygen from the air pockets of perlite particles. Also, water drains fairly quickly so there is enough air in the soil.

– What Is Vermiculite?

Vermiculite is a naturally occurring silicate of aluminum, iron and magnesium. Vermiculite also expands when you heat it. Unlike perlite, however, vermiculite can quickly absorb moisture in its air pockets. Vermiculite usually occurs at a neutral pH of 7, but it can raise the soil pH a bit.

Perlite vs Vermiculite Characteristics Plant America

The moisture retention ability of vermiculite is its major difference from perlite. While perlite can drain moisture, vermiculite retains moisture. Some uses of vermiculite are listed below.

  • Retain Consistent Moisture

Vermiculite is like a sponge that retains water. Even when the soil around it is dry, there can still be moisture within vermiculite. This means that your plants will have access to water even in dry soil when you amend the soil with vermiculite.

  • Soil Nutrient Amendment

Vermiculite attracts and absorbs nutrients such as potassium, phosphorus and calcium. These mobile nutrients are readily available to your plants when you amend your garden soil with vermiculite.

  • Helps With Soil Weight

Even though vermiculite is not as lightweight as perlite, it is still not as heavy as regular soil. You can amend your soil with vermiculite to reduce its weight just like perlite.

Which One To Use in Your Garden

In this section, we’ll let you know some common garden situations and whether you should use vermiculite or perlite for them.

– Perlite

Use perlite if the following cases are relatable:

  • When you want your soil to dry out quickly: To help your soil quickly become dry for plants such as tomatoes, you can either make a raised garden bed or amend it with perlite.
  • You have a succulent garden: Succulent plants do not like moisture in soil. They prefer dry soil with occasional watering. Using perlite in a succulent garden is almost always advised. It is not so advisable to use vermiculite for succulents.
  • You want to amend your clay soil: Clay soil might have a lot of nutrients, but people do not plant in clay soil often because plants suffocate in it quickly. To help amend your clay soil so that you can plant in it, mix in some perlite. 

– Vermiculite

Here are some cases when you should use vermiculite:

  • You forget to water your indoor plants a lot: Many indoor plant owners forget to water their plants. If you can relate to this, you should add more vermiculite in the potting mix and apply mulch so that it can retain more moisture.
  • You need a consistently moist soil: Some plants such as dill require soil with consistent levels of moisture. This means that no part of the soil should be dry or soggy. To achieve this, you should amend the soil with two parts vermiculite and one part perlite.
  • When you are growing seedlings: Vermiculite helps to maintain the temperature and moisture of the soil, so you will not be exposing your seedlings to immediate temperature fluctuations if you grow them in soil with vermiculite.
  • You grow mushrooms: If you are a mushroom grower, try adding more vermiculite to their substrate for better growth. Remember that mushroom substrate should always be moist.

Now you know the specific situations when you should use either perlite or vermiculite. How do you amend your soil with perlite, vermiculite or both? Find out in the next section.

How To Amend Soil With Perlite, Vermiculite or Both

Here is how you can amend your garden soil with these substances:

– Perlite Alone

Here’s how you can amend your soil with perlite:

  • Loam Soil

You can amend your loam soil with one part loam and one part perlite. Loam soil is nutritious and only needs perlite for the purpose of water drainage. For potted plants, add more perlite for quicker drainage.

  • Sandy Soil

You do not need to amend your sandy soil with perlite as sand drains water quickly. You can even amend other types of soil with sand instead of perlite.

  • Clay Soil

You should mix at least two parts of perlite with one part clay soil. Clay soil retains a lot of moisture so if you want to plant with it, you need more perlite. You cannot use clay soil for container gardening.

– Vermiculite Alone

Amend your type of soil with vermiculite using the guide below:

  • Sandy Soil

Even though vermiculite holds moisture, it is not the best choice when amending sandy soil. You should amend sandy soil with compost, rotted manure and other organic materials to help it retain moisture (and nutrients).

  • Clay Soil

While vermiculite is better than clay soil in the context of drainage, vermiculite is not the best to amend clay soil. You should use perlite or sand to amend your clay soil so that it can drain water quickly.

  • Loam Soil

You should amend your loam with one part soil and one part vermiculite to help the soil retain more moisture. Take note that it helps to amend your loam with both perlite and vermiculite.

– Using Both Perlite and Vermiculite

How can you amend your type of soil with both perlite and vermiculite? Take note that perlite is not a vermiculite alternative and neither is vermiculite for perlite. Here’s how to amend your soil with both products:

Using Both Perlite and Vermiculite Plant America

  • Clay Soil

You do not need vermiculite when amending clay soil. You can, however, mix a little vermiculite with two parts perlite and one part clay.

  • Loam Soil

According to the type of plant, you can mix one part loam with halt to one part perlite and half to one part vermiculite.

Loam Soil Perlit Plant America

Use more perlite for drainage and more vermiculite for moisture retention.

  • Sandy Soil

First, amend your sandy soil with organic matter. If it drains water too quickly, add vermiculite. If you want it to drain more water, add perlite. Make sure that you pay attention to the nutrients of the soil.

Congratulations! You now know how to amend soil with perlite, vermiculite or both.

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