What are the Best Perlite Alternatives?
What are the best alternatives for perlite? This is a common question that has been on the minds of many gardeners considering that perlite can be expensive and is not always easy to find!
Well, if you’re looking for a perlite alternative, you’ve come to the right place.
In this blog post, we will explore some of the best perlite alternatives and how they can be used in your outdoor garden, hydroponic system, or potted soils.
We will also discuss some of the pros and use applications of each option so that you can make the best decision for your needs.
What is Perlite?
Perlite is a lightweight, sterile, and inert clay-like amorphous volcanic glass commonly used in horticulture as a soil amendment or growing medium.
The largest component in perlite is silicon dioxide, but there are also other micro components such as oxides of Magnesium, Calcium, and Potassium.
Perlite has excellent drainage and aeration properties and can help regulate moisture and humidity levels.
When heated, perlite pops like popcorn, expanding up to 13 times its original volume.
This increase in the surface area makes perlite an ideal material for horticulture, construction, and insulation use.
There are three grades of perlite: coarse, fine, and medium-grade perlite.
- Coarse perlite has the largest particle size and is the most commonly used type. It’s used in various applications, including horticulture for succulent mixes, construction, and filtration.
- Fine perlite is used in applications where more uniform particle size is required, such as in fillers and potting mixes for houseplants.
- Medium-grade perlite is used in applications where more consistent particle size is required, such as in building insulation and soundproofing.
However, perlite can be expensive and is not always readily available. Fortunately, there are a number of perlite alternatives that can be used in their place.
Below we’ll discuss 12 materials you can use as effective perlite alternatives.
Each of these materials has its unique set of benefits and ideal use applications, so it’s important to choose the one best suited for your needs.
1. Vermiculite (A perlite alternative for moist soil plants)
While perlite can be beneficial for some plants, it’s not ideal for all types of plants.
Plants that prefer moist soils, such as ferns, will not do well in soils that have been amended with perlite.
Vermiculite is one of the most popular perlite alternatives. It’s a lightweight material that is perfect for volume conversions. It also has excellent water retention properties, making it ideal for gardens in arid climates.
2. Pumice (A more nutritious alternative)
Though perlite is the most popular growing medium for hydroponic gardens, pumice may be a better alternative.
Pumice is a type of volcanic rock that is full of holes and pores. It is lightweight and has excellent drainage properties, making it ideal for hydroponic gardens.
Pumice is also more nutritious than perlite, as it contains a higher concentration of minerals.
This can benefit plants, as they can absorb these minerals more easily. Pumice is also heavier than perlite, so it can help anchor roots and prevent them from floating away.
Overall, pumice is a superior growing medium to perlite and can be used in all types of hydroponic gardens.
3. Rocks (A perlite alternative for windy areas)
Perlite is also extremely lightweight and may blow away if it isn’t mixed thoroughly into the soil. If you live in a windy area, it’s best not to use perlite.
Rocks are often overlooked as a possible alternative to perlite. However, rocks can provide many of the same benefits as perlite without the worry of wind damage.
Rocks are a heavier material, which means they can help to anchor down your plants. Additionally, rocks can help to improve drainage and aeration in your soil.
4. Coir (A lighter, natural, and more water retaining alternative)
Unlike perlite, coir is made from the husks of coconuts and is a sustainable resource.
Coir is also more effective at absorbing and retaining water while providing good drainage for your plants as it does not compact.
Coir is also lighter and easier to handle than perlite, making it a good choice for growers who don’t want to deal with the heaviness of perlite.
5. Wood chips (A sustainable and biodegradable perlite substitute)
Another alternative to perlite is wood chips. Wood chips are a byproduct of the lumber industry and are often freely available.
They can be used the same way as perlite, as a soil amendment, or a lightweight aggregate.
Wood chips are also biodegradable, which makes them a more sustainable option than perlite.
Wood chips are a popular substrate for growing plants, especially trees and shrubs. Since wood chips have a very high drainage rate, frequent watering may be needed.
6. Peat moss (A more absorbent, acidic, natural, and affordable alternative)
Peat moss is a popular alternative to perlite for many gardeners and horticulturists.
Peat moss is more absorbent than perlite, which means it can hold more water and nutrients for plants. Peat moss is also more acidic (pH 3.0-40) than perlite (neutral), which can be beneficial for some plants such as berries.
Additionally, peat moss is a more natural material than perlite, making it eco-friendlier.
Finally, peat moss is more affordable than perlite, making it a great option for those on a budget. A bale peat moss will cost you about $20.
7. Sawdust from untreated wood (A cheap and readily available alternative)
Sawdust from untreated wood is a great alternative to perlite because it is cheap and easy to find.
Plus, it has many of the same properties as perlite, such as being lightweight and having good drainage.
If you are going to use sawdust as a perlite alternative, it’s best to use sawdust that has been out in the weather for at least two months.
This will help ensure that the sawdust is dry and won’t compact too much when applied to the garden.
8. Sand (A perlite alternative that does not disintegrate)
One downside of perlite is that it can disintegrate over time, which can eventually lead to the soil becoming too dense.
One possible alternative to perlite is sand. Sand has similar characteristics to perlite in that it is lightweight and doesn’t compact over time.
However, sand is more durable than perlite and doesn’t disintegrate over time. This makes it a more long-term solution for use in potting soil.
9. Granite gravel (A weed-controlling and sustainable alternative)
Granite gravel is a type of rock that is similar to perlite. It is often used as an alternative to perlite for various purposes such as improving aeration, providing aesthetic purposes in topsoil, and controlling weeds.
Granite gravel is a harder rock than perlite, which makes it durable and long-lasting. It is also less likely to break down over time, which makes it a more sustainable option.
10. Horticultural grit (a decorative and antifungal alternative)
Horticultural grit is a type of coarse sand or gravel that is used to improve drainage in garden beds and pots. It is also used to provide a firm base for planting.
Horticultural grit is less dusty and can be more decorative than perlite, making it a popular choice for potted plants.
In addition, horticultural grit can help improve drainage, reduce compaction, and deter fungus in potted soils.
11. Rice hulls (A sustainable and environmentally alternative)
Rice hulls are the hard outer shells of rice grains. They are typically removed during the milling process.
Rice hulls are a renewable resource and can be used in a similar way as perlite. They are excellent at improving drainage and aeration and can also help improve the structure of sandy soils.
In addition, rice hulls are more environmentally friendly than perlite.
12. Calcined clay (A heavier and more moisture retaining substitute)
Calcined clay is a type of clay that has been treated with heat to remove water molecules from its structure.
This process makes the clay more durable and gives it a variety of new properties that make it an ideal alternative for perlite.
While calcined clay is heavier than perlite, it’s also more moisture-retentive. This makes it an ideal material for use in horticultural applications, where it can help to improve drainage and prevent root rot.
What is the best perlite substitute for succulents?
When it comes to succulents, one of the most important things you can do is provide them with adequate drainage. This can be achieved using a perlite substitute, such as horticultural grit.
Horticultural grit is a type of coarse sand that helps to aerate the soil and improve drainage. It can also help to prevent the roots of your succulents from rotting.
If you live in an area where perlite is not readily available, or if you simply prefer not to use it, horticultural grit is a great alternative.
Just be sure to use a product meant for horticultural use, not construction-grade sand, as the latter can contain harmful chemicals.
Another great perlite alternative for succulents is pumice. Pumice is a great alternative to perlite for succulents because it provides good drainage and aeration while still retaining moisture.
It is also less likely to compact over time, making it a more sustainable option.
What are the disadvantages of perlite?
Here are some disadvantages of perlite that you should consider before using it:
1. Perlite is a lightweight growing media, but it can be blown around by strong winds.
2. Perlite does not hold water, meaning it’s not ideal for plants that thrive in wet soils.
3. Perlite can be dusty, and it can irritate the lungs if inhaled.
4. Perlite is a sterile growing media, so it does not contain any beneficial bacteria or fungi.
5. Perlite can be expensive, and it’s not always widely available.
Does perlite contain asbestos?
One of the most common questions about perlite is whether it contains asbestos.
Asbestos is a mineral known to cause health problems, including cancer. However, asbestos is rarely found in volcanic rocks like perlite.
The chance of finding asbestos in perlite is very low, so this gardening material is not considered a health risk.
Can you use cat litter as a perlite alternative?
A layer of cat litter can help retain water in a potted plant and prevent the plant from drying out.
While cat litter can be a suitable substitute for perlite in some situations, it’s important to keep in mind that there are some potential drawbacks.
For example, cat litter is not as effective at aerating soil as perlite, and it can also introduce harmful substances into your garden.
Additionally, cat litter is not always easy to find in large quantities, which can make it impractical for some gardeners.
Can you use Styrofoam as a perlite substitute?
Styrofoam is an economical type of plastic that is often used in packaging materials.
It is lightweight and can be used to improve drainage in soil, and it’s also dense and can be used to bulk up the soil.
However, styrofoam does not decompose, which means it can stay in the environment for a long time.
So, should you use styrofoam as a perlite alternative?
Well, if you have some styrofoam that you are looking to send to the landfill, it’s better to use it in your potting mixes.
Just don’t use it in outdoor soils as it’s not environmentally friendly. It’s good to be aware of the following when using styrofoam as a perlite alternative:
1. Styrofoam is an inorganic material, so it does not provide any nutritional value to your plants.
2. Styrofoam will compact over time, so it is important to fluff it up regularly to ensure good drainage.
3. Styrofoam is light and can easily be blown away by the wind. Make sure to secure it well, so it doesn’t become a litter problem.
What is a cheaper substitute for perlite?
Wood chips, sawdust, and coir are all cheap substitutes for perlite. Wood chips and sawdust can be found for free if you have access to a woodworking shop.
Coir is a type of coconut fiber that is often used in hydroponic growing systems. It’s also available in horticultural stores at very affordable prices.
Who needs Perlite when you’ve got all these other great options? From vermiculite to calcined clay, there are plenty of options to choose from.
So whether you’re looking for a cheaper alternative or something that’s more environmentally friendly, this guide got you covered.
And no matter which perlite alternative you choose, you can be sure that you are making a decision that is best for your plants and your garden.