This page contains affiliate links.
Substrate, or “bedding,” is the material that is used to cover the bottom of your mourning gecko enclosure. The right mourning gecko substrate can help maintain humidity, while others won’t — and some can even make your pets sick!
Good mourning gecko substrates:
Lugarti Natural Reptile Bedding: My personal favorite substrate for small tropical and semi-tropical reptile species. Holds humidity well, not dusty, and smells nice. It is one of the more expensive substrate options, however.
Zoo Med Reptisoil: Designed specifically for terrariums with live plants. Not the greatest at holding humidity, and tends to get muddy when wet.
Sphagnum moss: Great as a substrate by itself or mixed into your main substrate. Soft and holds humidity very well, but feeder insects tend to hide in it.
ABG Mix: Substrate mixture developed by the Atlanta Botanical Gardens. Great for live plants, holds humidity very well, and works perfectly as a bioactive substrate.
The Bio Dude Terra Fauna: Bioactive substrates and enclosures are nice because they use symbiotic relationships between the animals (in this case, mourning geckos) and certain detritivore species to break down waste. The result? Essentially a self-cleaning terrarium, which is perfect for dealing with mourning geckos. This substrate in particular has an optional bioactive substrate kit that I highly recommend. For more information on bioactive, read the files in Reptile & Amphibian Bioactive Setups.

Mourning geckos spend very little time on the ground. Photo by Woodland Manor Darts and Dragons @WMD_n_D
Bad mourning gecko substrates:
- Coconut fiber
- Coconut husk
- Cypress mulch
- Wood shavings, especially pine/cedar
- Reptile carpet
Most of these substrates pose a substantial risk of injury. Additionally, reptile carpet fibers can catch and damage delicate gecko toes, as well as encourage bacterial growth. Pine/cedar oils are well known to cause permanent neurological damage in reptiles.
How to Layer Your Substrate
One of the best ways to maintain humidity and prevent mold in your mourning gecko terrarium is to create a drainage layer underneath the substrate. It sounds complicated, but it’s actually really simple.
All you need is a bag of clay balls and some landscaping mesh. Pour enough clay balls into the bottom of the terrarium to make a 2” deep layer, add some distilled water, and then cover with the mesh and a 2-4” layer of your substrate of choice.
a