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4 Best Substrate For Tarantulas

The best tarantula substrates are the most natural ones and include Top soil, vermiculite, peat moss and coconut husk.

If you have a tarantula and just want to upgrade its tank or are preparing to bring a new one into the right home, we’ve got a few substrate suggestions for you.

There are a lot of good brands on the market, but what makes a substrate good or bad? What should you look for and what should you generally know about when looking at substrates?

We will answer all your questions to ensure that your pet tarantula will stay happy and healthy in their enclosure.

If you are in a hurry, here are the 5 best. The buying guide is below the products and explains all the options and things to consider.

Tarantula Substrate Comparison

Best Substrate For Tarantulas

Here are some of our recommended products, a little about them, and links to where you can buy them.

1. T-Rex Reptile Terrarium Substrate

T-Rex’s Forest Bed is made up of coconut husk, meaning it is eco-friendly and perfect for a more naturalistic setup, since it can double as a nutritious soil for plants. This absorbent substrate will help increase the humidity in your tank if it is kept damn, which can be ideal for some tarantulas.


The best thing about this specific brand of substrate is that it looks naturalistic, just like any regular soil. They are also easy to store since they come in bricks that can easily be activated and expanded with water.

It is a great water absorbent, making it great for natural humidity in your spider’s enclosure. This is perfect for burrowing tarantulas and any species that require higher humidity.

Coconut fiber really is the best substrate you can add to your pet’s tank.


The only real downside to this substrate is the price. Compared to other options, this can be relatively expensive. All in all, you get what you pay for, though.

Some people see this as a bad thing, but coconut fiber can get a little fluffy once it has finally absorbed all the water and has dried out. 

It can get a little bit messy, but that depends on the user and if they find that annoying.

2. Scotts Organic Group Proom Top Soil

This brand of topsoil is a good gardening soil, but it also makes a great substrate for your tarantula enclosure! This premium topsoil is organic and has peat moss already added.

We’ve already checked the labels for you so this is safe for your tarantula for sure!


Besides this being pesticide-free and organic, the price is also a huge plus. You can get lots of it for a low price and you will always be prepared for tank cleanings.

This topsoil is suitable for mixing with other substrates in order to add some bulk. It is also great for burrowing tarantulas since they can be packed down tightly.


This topsoil is very bulky and heavy and may also cause some puddling if you spray too much water into the enclosure.

3. Organic Sphagnum Peat Moss by Perfect Plants

Peat or Sphagnum moss is a great substrate for both arboreal and terrestrial tarantulas that require a little more moisture in their tank. Both mosses mix well with other substrates and both produce the same outcome.


This substrate packs very well for burrowing species and is very water-absorbant. It can be combined with both coconut fiber and topsoil, making for a great mix.

It is also very inexpensive when bought in bulk, which can be a plus for those on a budget.


This substrate can contain some jagged pieces, so please do check and remove them before putting them in your spider’s enclosure.

Moss tends to mold easily so you need to be careful of the amount of water you are using to wet their bedding. Make sure you are keeping an eye out for mold and removing any mold as it appears.

4. Josh’s Frogs Vermiculite (1 Quart)

This vermiculite can be great in loosening up your topsoil by providing aeration, conditioning it, and also allowing for better drainage. If you have a naturalistic terrarium, your plants will be thriving with this added into the mix.


It is very water-absorbant, lightweight, and still unlikely to mold. 

It isn’t hard to find in-store and will just add to the overall wellbeing of your tarantula terrarium.


Again, this is an additive and should not be used by itself. Alone, tarantulas will not like the feeling of it and will not walk on it anyways.

Another downside is that it isn’t very sightly, but that opinion can vary from person to person.

What to Look For: A Buyers Guide

There are a few things you should first consider when shopping for the best substrate. 

First, consider what species your tarantula is. The bedding or substrate you use should mimic the environment they are native to. Where they come from can be a huge hint as to what kind of needs should be met when choosing the right substrate.

Consider the temperature of your tarantula’s natural habitat. Most tarantulas will live in sub-tropical, tropical, or desert areas.

Sub-tropical and tropical tarantulas will need diverse levels of heat and humidity that will accurately mimic their native homes. This means you need a substrate that holds water well, which can be a little tough.

They will require a substrate that is wet at the bottom while simultaneously staying dry up top. Bedding that is too wet will cause your spider to want to climb away from it, making it susceptible to a fall, possibly getting injured.

Wet bedding can also cause mold and fungi, which may or may not harm your spider by causing illness or even killing it. Avoid this issue by making sure the top bedding is dry and only the bottom is moist.

Also, make sure that your tarantula’s enclosure has proper ventilation as this will allow airflow, while still holding the humidity needed. 

In terms of heat, tarantulas do not need lighting to survive. It can actually be harmful to them. 

It is best to keep a heating pad on one side of their tank when needed.

They actually thrive at room temperature, where we are comfortable anyways.

The next thing to consider is whether your tarantula is a ground-dweller or arboreal, meaning they climb or live in trees. 

Terrestrial or grown-dwelling tarantulas will need more ground coverage since their enclosure will need to be more spacious. They will need sturdy bedding that is softer since their bodies can’t take a fall as well as their arboreal counterparts.

On the other hand, climbing tarantulas will be less heavy-bodied and will also need a bit of height in order to climb or build nests around inside their tank. Withstanding a fall will be a lot easier for them so you won’t need to consider the softness of your bedding like you should with terrestrial spiders.

Another thing to consider is whether or not your spider is a burrower. Burrowing tarantulas are actually a sub-category of ground-dwelling spiders that will need a substrate that is strong enough to stay put and not collapse on them as well.

A good burrowing substrate would be a good mix of coco fiber, topsoil, and peat moss. Be sure to pack down the substrate tightly, allowing your tarantula to create a burrow that will hold.

Just remember to provide them with a hide for them and a shallow water dish.

Substrate to Avoid

Save yourself the hurt that would come with the experimentation of substrates you aren’t sure about but want to know about. 

Trust us, here are some substrates and things you should avoid experimenting with:

Jagged or sharps

Don’t forget that tarantulas are quite fragile, no matter how strong they look. A short fall of a few feet could kill your pet and even a small slip in their own enclosure could injure them.

Make sure to avoid using sticks, bark chips, or any other jagged pieces as a substrate since sharp edges can rupture its abdomen. Save your pet by avoiding these in the first place.

Fertilized Substrates

Read all the labels on your substrate choices and make sure that there are no fertilizers or additives in them. You can use soil for your tarantula’s enclosure but check the labels for fertilizer, animal waste included, and even if it says it’s organic.

Cedar or Pine Chips

Avoid anything that might have any compounds of conifers or cedar in it because they may be harmful to your tarantula. This is only a speculation and some owners still use peat moss mixes with pine or cedar in it.

But it is always better to be informed; better safe than sorry!

Aquarium Gravel

Not only will this hold water way too well, leaving puddles beneath the surface, but this substrate is too jagged for your tarantula. It will not be good for them in the case of a fall.

It is also highly frowned upon within the tarantula community due to these issues (for good reason) so you should just avoid it.


Although it is not the worst substrate, it is still not recommended since it will not hold well in the case of burrowing, it will not hold water, and your tarantula might not even like standing on it.

It is ok to sprinkle some in on top of your substrate or mix a small amount in, though. Just make sure you do your research.

Corn Cob Granules

This should be avoided at all costs because they are organic and can mold very quickly due to the humidity, which will cause many issues that you will have to deal with. It also just doesn’t look good, aesthetically, in general.

Even though a few of the ones mentioned above might be fine in small amounts and maybe if mixed in with other substrates, this one is generally a no-go.

Types of Substrate

Coco Fiber 

Coconut is absorbent, mold-resistant, and is great for tarantulas from more arid climates. It can be used for humid environments as well when mixed with other substrates.

Originally used for gardening, these fibers will create a similar effect to that of soil, just without the minerals or additives that come with soil. The texture and appearance will be similar to normal earth, which is the consistency you are looking for in a substrate.

You can buy these at your local gardening center in large blocks or might even be able to find reptile-friendly bricks at your local pet shop. 

If you decide to buy from your garden center, you just need to remove the highly compacted bricks out of their original bags, rinse it with water, then drain after it expands, and it should be ready to use in your spider’s tank.

You can mix in small amounts of sand, vermiculite, or topsoil with your coco fiber as well to create different effects that might better suit your pet’s tank. 

This substrate is effective and adaptable, making it the most recommended substrate for your pet tarantula.


Topsoil can also be a great substrate for your pet tarantula and it’s easy to find at your local garden center. You can use it just by itself or mixed with coco fiber. 

Make sure you are only buying topsoil that is free from additives or fertilizers, as they can be toxic to your pet spider. Read the labels carefully, even if they say they are organic.

Topsoil is suitable for tarantulas that don’t have any particular needs.

When you bring it home from the store, you can sterilize the topsoil by baking it in the oven or boiling it in water to kill any possible parasites or other bacteria. You don’t want your tarantula getting ill.

Peat Moss 

Peat moss is an inexpensive substrate that can also be purchased at your local gardening store. It is made from sphagnum moss, which will be great for holding moisture.

This is a great choice for any species of tarantulas that require more humid environments. 

The same rules apply to peat moss as the topsoil; read your labels and look out for any additives or fertilizers, even if the bag says it’s organic.

Vermiculite as an Additive

Vermiculite is a mineral substrate that will absorb moisture efficiently, helping with water retention and humidity. 

This should not be used as a substrate since tarantulas do not like standing on it and will show it by standing on their “tiptoes”. However, it is commonly used by hobbyists as an additive along with other substrates to aid in moisture retention.

This substrate is a great and important addition to add into a substrate mix since it facilitates burrowing needs.


After you’ve picked out your substrate or mix, make sure it is clean. If you bought it from a gardening store, get rid of any bacteria by boiling it with water or throwing it in the oven and allowing it to cool down.

If you bought your substrate from a pet shop, you might be able to use it right away without having to sanitize it, but ask your seller first.

A good rule of thumb is to give your tarantula at least five inches of the substrate to allow ample space for exploration. 

When adding substrate or bedding to your tarantula’s tank, you should provide at least three inches of substrate at the bottom that will hold moisture or provide warmth.

After adding in your substrate, be sure that measurements from the surface of your substrate to the enclosure’s peak are optimal. Make sure the heights are not higher than your spider’s full length in order to avoid any deadly falls or possible injuries.

Check out this video on how to set up a terrarium for your tarantula:


So which is the best substrate for tarantulas?

The simple answer is coco fiber mixed with topsoil. These two will bring together a perfect harmony of moist and arid, giving owners the ability to adjust and add anything else that might be needed in terms of bedding.

This mix can be used with many different kinds of enclosures and will also create an all-around more naturalistic-looking terrarium.

Notice we recommend mixing substrates and also providing what your specific species of tarantula needs as well. But overall, we can’t recommend coconut fiber enough!

Leave any comments below telling us what substrate you use in your tarantula’s enclosure. Also, let us know what kind of tarantula you have!

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