Sphagnum moss is a type of long-fiber moss that is used both chopped up on the bonsai soil to favor the formation of natural moss on the substrate, and mixed with the soil to improve water retention. Sphagnum moss is able to absorb a quantity of water 20 times higher than its weight, forming a moist but oxygenated mass, in which the roots thrive without any problem of asphyxiation; it is used in layering and as a mulch to protect the roots from winter frost. Sphagnum moss is very soft and added to the substrate of the pots it makes the soil much more aerated and ventilated, continuing to release useful substances and generating a slightly acidic environment.
