Espoma Organic Charcoal is an all-natural high carbon material that helps improve soils. It is produced by heating untreated hardwoods to very high temperatures without oxygen in a process called pyrolysis. The result is an excellent soil conditioner for potting mixes that improve drainage in containers. For Containers with Drainage Holes: Add up to two cups of Espoma Organic Charcoal for each cubic foot (1 heaping tbsp. per quart) of potting soil. For best results add the appropriate amount of Bio-tone Starter Plus. Mix thoroughly, fill your container and plant your plants. For Containers without Drainage Holes: Add a 1 to 2 inch layer to the bottom of the container before adding potting mix. For Terrariums: Thoroughly wash & dry container prior to planting. Add a layer of small gravel to the bottom of the terrarium. To that add ½ to 1 inch layer of Espoma Organic Charcoal. Add a 1” layer of sphagnum peat moss to help prevent potting mix from seeping into the drainage area. Now add Espoma Organic Potting Mix and you are ready to plant your terrarium