Perlite Substitute: Read All About the Best Possible Options

If you are growing plants, then you want the best possible growing medium for them. One cannot expect a good yield without any proper medium. However, sometimes a good growing medium is either not accessible or too expensive to buy. In that case, we must start to look for substitutes. One perfect example of this is the Perlite substitute. A good gardener always has a backup if any emergency occurs.

This article is one aspect to deal with the “Perlite Non-availability” emergency.

What is Perlite?

Perlite is a granular substance that does not decompose. It is mixed with the soil to improve the soil’s structure. It is a highly recommended substance that does not even change its shape when it is added to the soil.

Generally, it is added to the potting mixes to aerate it. Aeration is necessary as roots development depends upon it. Due to its non-decomposition characteristic, it is perfect for potting mixes. When you add perlite, the soil becomes more porous. Thus, the draining capacity is enhanced. Moreover, the soil becomes loose and compaction is defied. This makes roots a happy camper as they can now grow easily.

But what will happen if there isn’t perlite available? There could be many reasons this problem may occur like perlite is out of stock or is too expensive for you to buy etc. In this situation, look for a perlite substitute. Lucky for you, in this article, we are describing 12 substitutes for perlite you can use in gardening.

Perlite substitute.
Perlite adding to the soil.

Let’s take a look at some perlite substitutes.

Perlite substitute: Let’s look at the Possible Options

Perlite substitute selection depends upon the type of plant grown and the conditions. Type of plant grown means whether the plant requires more water or less water. Conditions mean whether the plants can tolerate high or low pH or not. We will discuss both plant types and conditions and their relation with perlite substitutes.

Let’s have a look at possible substitutes for perlite in Potting Mix you can use:

  • Sand
  • Vermiculite
  • Bark
  • Peat
  • Calcined clay
  • Pumice
  • Rice husks
  • Coir
  • Horticultural grit.
  • Granite gravel.
  • Cat litter
  • Styrofoam

Sand

Sand can be selected as a perlite substitute. Sand and perlite have many similarities like:

  • Both have neutral pH.
  • Both are sterile.
  • Both are nutrient-free.
  • Both facilitate drainage.

Due to these similarities, gardeners use sand in place of perlite. Clay-heavy or compact soil is a good choice for this. Ideally, you should choose coarse sands. This can be a good substitute for perlite in potting mix.

  • Note: Just keep in mind that sand is heavier than perlite for potted plants.

Vermiculite

Vermiculite is another substitute for perlite. It is a highly absorbent mineral. Just like sand, it has many similarities with perlite. These are:

  • Both are lightweight.
  • Both have neutral pH.
  • Both don’t decompose.

Vermiculite improves soil aeration and roots can receive more oxygen. Moreover, it is also known to improve soil structure.

The thing that distinguishes vermiculite from the rest is that it acts like a sponge. It soaks up water and nutrients and retains them in it. Due to this property, vermiculite is the perfect substitute for those plants which require more moisture levels at roots. So, a Substitute of perlite can make growing easy!

As a matter of fact, vermiculite is more absorbent than perlite. This characteristic is also its limitation. Vermiculite cannot be used for those plants which don’t require much moisture or nutrients. Such plants can get negatively impacted due to the continuous presence of moisture around the roots. Examples are cactus and succulents.

Bark

The bark is widely used in commercial potting mixes. Bark offers many advantages like:

  • It slowly releases nutrients to plants
  • It improves drainage and enhances water retention capacity.
  • It improves soil aeration and prevents soil to compact.
  • It is both organic and biodegradable, making it a perfect medium for both indoor and outdoor gardening.

If you want to use Bark, then let us warn you about one thing. The bark is a little acidic in nature. Pinewood bark pH ranges between 4-5. However, this can prove to be a blessing for those plants which require high pH to grow. These include carnivorous plants, ferns, and magnolias. So, it can be a substitute for perlite in gardening.

Peat

The other name of peat is Sphagnum moss and is widely used in potting mixes. It offers the following advantages:

  • Water retention capacity is high in peats.
  • It improves soil aeration and allows roots to access oxygen properly.
  • Peat keeps the soil wet for a longer period.

Due to its advantages and popularity, some gardeners even replace the soil with peat altogether. Peat is a perfect medium for plants like tomatoes, blueberries, and other acidic soil lover plants. Both peat and bark are similar to each other due to their acidic nature.

Let us tell you a major disadvantage of using peat. Although peat is biodegradable, its mining is not environmentally friendly.

Calcined Clay

This medium is available under the Turface brand. Calcined clay is just like perlite with just two differences. The first difference is that Calcined clay is more absorbent than perlite. So, it absorbs more water and keeps it around the roots. If you are growing plants that love moisture, then calcined clay should be your pick. Moreover, calcined clays are used on the grounds, and playing fields.

The other difference is that Calcined clay is heavier than perlite. So, if you water plants or during heavy rainfall, calcined clay doesn’t easily wash away as compared to perlite.

Its advantages are just as same as perlite like it improves aeration, and increases water retention capacity.

Moreover, Calcined clays are highly recommended but keep in mind that they will start breaking after few years.

Coir

Coir or Coco Coir is a fiber of coconut husk. Coir is often compared with Perlite as is considered an effective perlite substitute. Why? Due to their uncanny similarities which are:

  • Both are lightweight in nature.
  • Improve the drainage.
  • Improves aeration.

Let’s take a look at where they both differ. Coir has more water retention ability than perlite. Thus, if you are growing plants that require more moisture, then go for Coir. Moreover, Coir is acidic and you have to be careful regarding that.

  • Note: Don’t grow pH-sensitive plants in this medium.

There is only one limitation when it comes to Coir. If you are using Coir, remember that coir has no nutrients of its own. You have to keep fertilizing for nutrients available to plants.

Rice Husks (or Hulls):

Rice Husks or Hulls can also be used in place of perlite. You can use it in both outdoor and indoor gardening. Let’s have a look at their advantages:

  • Environmentally friendly
  • Organic.
  • Control weeds.
  • Lightweight in nature.
  • Improves overall soil health (Aeration, drainage, etc).

It is a DIY perlite substitute. However, there is one slight disadvantage. Rice husks or hulls are lighter than the perlite. Thus, when you add water to the rice husk mix, it will start floating on top of the soil.

Granite Gravel

Although both look very different, yet they both serve the same purposes. Both play their roles in improving the soil. However, Granite gravel is heavier than perlite. Granite Gravels are that much heavier that even their small pieces don’t get washed away. Let’s have a proper look at Granite gravel benefits:

  • Granite Gravel can control the weed problem.
  • It improves soil health by improving aeration and drainage.
  • It increases the water retention ability of plants which amkes it ideal for those plants whcih require more water to grow.
  • It is aesthetic and increases the beauty of your garden.

But it has some disadvantages as well. As they are heavy, then if you fill small pots with granite gravel, they will still be difficult to lift. Moreover, due to its weight, germination is affected as seedlings have to work harder to get out.

Horticultural Grit

Grit is commonly made up of small stones. These stones range from 2mm-4mm in size. It can also improve soil health and play its role in the proper development of plants and become a perlite substitute. However, it is heavier than perlite.

Its advantages are:

  • Grit is a fungus gnats Repellant.
  • It gives aesthetic look to your garden.
  • It improves the soil and its abilities.

So, Horticultural Grit can e a good perlite substitute for plants.

Pumice

Pumice and perlite are similar as both are formed after the eruption of volcanoes and both are porous. Check out what are the advantages of Pumice that makes it attractive:

  • Pumice is heavy which means it does not experience erosion.
  • It produces less dust, thus it is eco-friendly.
  • It has high nutrients and minerals in its composition.
  • It improves soil aeration, compactness, and water retention.

One drawback of Pumice is that it is very expensive. So, gardeners don’t prefer it as a substitute for perlite.

Cat litter

Many people don’t know this but we can use cat litter in a potting mix. It can prove to be an excellent substitute for perlite due to the advantages it brings to the table. Let’s take a look at the reasons why we think kitty litter is good for houseplants:

  • It is light-weight.
  • It is cheaper than most of the substitutes.
  • Improvs the condition of the soil (Reduce compactness, improve drainage, and aerate the soil)

It is a great addition to the soil on which the succulents are grown. So, you can use cat litter instead of perlite.

Styrofoam as Perlite Substitute

Styrofoam is also known as extruded polystyrene foam. There are a few forms of styrofoam available, however, you must opt for thick styrofoam meat trays. These thick styrofoam meat trays are cut into strips and mixed with water before being added to the soil. Thin styrofoam doesn’t work as it becomes snow-like and too light when water is mixed.

Styrofoam has many advantages which makes them a viable option as a perlite substitute

  • It is the cheapest perlite substitute.
  • Lightweight in nature.
  • Excellent compound to improve soil health.

It is not 100 percent good as it has some limitations as well. With time, it starts compressing. Thus, the aeration benefit it provides diminishes after some time. Moreover, its lightweight nature may make it float in water during irrigation.

Bottom Line

All-inclusive, we must choose perlite substitute carefully. Which substance you want to add to the soil will affect its health. Different plants require different growing mediums. Perlite is also added to enhance advantages like soil aeration, better moisture and nutrients retention, and less compact soil. To get a substitute, we must consider plants’ requirements and choose the best option available. The 12 substitutes we have provided are the most commonly used. What do you think is the best perlite substitute? Share with others by commenting in the comments section down below!

FAQs

What is a cheaper alternative to perlite?

The cheapest alternative to perlite is styrofoam. It is a chemical that is produced artificially and is also known as extruded polystyrene foam. It is in many forms but the best one we must use is thick styrofoam meat trays. These are available at any market and are inexpensive. These trays are first chopped into strips. Then water is added to it and this mixture is applied to the soil. It works just as efficiently as perlite.

Can I use gravel instead of perlite?

Yes, you can use gravel instead of perlite. Gravel is known to control weed problems, improve soil conditions and give your garden an aesthetic look. But gravel has some disadvantages. Its weight is its first limitation. If you fill a small pot with gravel, even it becomes difficult to lift. Moreover, seedlings can’t emerge in this medium.

Can I use Styrofoam instead of perlite?

Yes, you can use styrofoam instead of perlite. Due to several reasons, perlite is not available everywhere to everyone. In that situation, you have to start looking for substitutes. One best substitute you can opt for is styrofoam.

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I am a graduate in Agriculture Sciences and have experience of four years in this field. I am also a professional and certified Content Writer. I do extensive research to enrich readers with such knowledge that helps them in the long run.