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Vermiculite vs Perlite | When and How To Use

Do you know the difference between vermiculite vs perlite? Whether you’re an avid gardener or starting out, it is highly likely that you’ve heard of perlite and vermiculite.

Many of our own gardening guides mention adding either perlite or vermiculite to the soil to help support your plants. Although these two soil additives are quite similar, there is, in fact, a very important difference and purpose for your plants. 

So, how do you know which one to use when? Follow our guide for everything you need to know about vermiculite vs perlite. 


Vermiculite vs Perlite When and How To Use

Vermiculite vs Perlite - Which Should You Use?

Vermiculite vs Perlite When and How To Use

When it comes to indoor plants or seeding mixes, you will often come across the phrase perlite or vermiculite. These additives are a great way to support and improve soil, making it an ideal growth environment for what you’re hoping to grow. 

However, choosing the wrong additive can become a problem, as vermiculite and perlite really aren’t interchangeable. The key to making the right choice is understanding what these additives are and, in turn, what they’re good for. 

What is Perlite

What is Perlite?

Perlite is a small, lightweight, odorless soil additive made from volcanic rock. This volcanic rock is heated and then crushed to form small specks of rock. 

These specks of rock are often added to soil mixtures to boost soil aeration, increase humidity without too much moisture and improve soil drainage for soil-based potting mixes.

Perlite has lower water retention, which makes it a perfect additive for plants that enjoy drier, well-draining soil. Perlite also helps to insulate plant roots which can protect them from major temperature fluctuations. 

It is often used for indoor plants. However, it can be added to soil when moving plants that are used to a warm, indoor space outdoors. 

Benefits of Using Perlite

The biggest benefits of perlite include:

  • Easy to handle and easily blends with soil mixes. 
  • Effectively loosens heavy, compact soils. 
  • Improves soil for cuttings. 
  • Prevents rot and mold within the soil. 

Plants that do well with a perlite soil mixture include: 

How to Use Perlite

How to Use Perlite?

Perlite can be used when planting plants where well-draining soil is an absolute must. This, again, can be mixed with a peat moss or potting soil mixture. 

Most often, gardeners will add 1/3 mixture to soil. However, when it comes to orchids and succulents and ½ perlite ½ soil mixture is often more suited. 

A layer of perlite can also be added over lawns to keep them well aerated and protect grass in the winter. Perlite is also a great option for storing bulbs over the winter. 

What is Vermiculite

What is Vermiculite?

Vermiculite is a magnesium-aluminium iron silicate. This all-natural mineral product is brown or beige in colour and is most often used to improve water and nutrient retention in soils. 

This silicate absorbs and holds lots of water which helps to keep the soil moist over a long period of time. This is why many gardeners recommend using vermiculite for plants that enjoy overly moist soil.

More so, vermiculite doesn’t only absorb moisture but nutrients too. Vermiculite is sometimes used for indoor plants, especially tropical plants that enjoy a moist and humid environment.

However, because vermiculite can make the soil more compact, it doesn’t aerate the soil as well. This is why vermiculite is often used outdoors, so improve sandy soils or as part of a potting mix. 

Benefits of Using Vermiculite

The biggest benefits of vermiculite include: 

  • Boosting soil nutrient retention. 
  • It easily blends in with soil. 
  • It’s sterile, non-toxic and PH balanced. 
  • It’s perfect for seed starting mixes. 

Plants that do well with vermiculite mixtures include: 

How to Use Vermiculite

How to Use Vermiculite?

Vermiculite can be used when growing seeds, when potting plants for indoor growth, for composting and even for your lawn. For potting, you can mix vermiculite with peat or another potting medium to improve drainage. 

Depending on the plant you’re growing, you can fill your pot with as much as 1/3 or a ½ of vermiculite. Avoid adding vermiculite to the soil during the winter, when moisture can be tricky for plants. Rather add vermiculite during the spring. 

For new lawns, a ¼ inch layer of vermiculite can be sprinkled over the lawn, which will help to encourage growth and health. 

What is the Difference Between Perlite and Vermiculite

Difference Between Perlite and Vermiculite

As made clear by the benefits for each additive and the obvious visual differences between perlite and vermiculite, there are some other major differences between the two. 

Another major difference between perlite and vermiculite is the difference in PH levels. Vermiculite is the most neutral of the 2, with a neutral PH level of 8. Perlite is slightly more acidic with a PH level of 6.6 to 7.5. 

Perlite is also a slightly harder material. However, neither material will rot, deteriorate or decompose. When debating between perlite vs vermiculite, it’s most important to consider the purpose. 

What are you hoping the additive will do? What are you trying to improve? Perlite is the perfect choice for plants that need aerated, well-draining soil. 

Vermiculite is the perfect choice for plants that need a little extra moisture and nutrients. Using perlite on plants that need moisture, will cause plants to dry out. 

Equally so, using vermiculite with plants that require dry soils may cause root rot. 

Looking for more answers to your garden questions? Take a look at all of our gardening solutions here.

Now You Know The Difference Between Perlite vs Vermiculite

So, there you have it. Everything you need to know about perlite and vermiculite, as well as when and how to use it. It’s always a good idea to check your plants’ needs before planting to know exactly which one to use in your soil mixture. 

About the Author Mabel Vasquez

Mabel has enjoyed a long career as a horticulturist, working in nurseries and greenhouses for many years. Although she loves all plants, Mabel has developed a particular passion over the years for herb gardens and indoor plants. Mabel has since retired from her horticulture career and loves sharing her many years of experience with our audience here at Sumo Gardener.

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