What type of soil works best in terrariums? Coco – coir, peat moss or houseplant soil works with most plants, besides succulents which prefer a well-drained inorganic medium. Some people choose to make their own soil but if you're short on time, garden store houseplant soil works just fine.
Charcoal is an important element in a terrarium because it helps remove toxins and odors. If you don't have charcoal, you can still make a terrarium, but you'll need to to take extra steps to ensure your plants remain healthy and that the environment inside your terrarium remains clean and odor-free.