Chamber. It refers to facilities to protect bonsai trees against damage from frost, freezing or snow in the winter season. A prefabricated house, plastic greenhouse or any other closed chamber is fine for such ”muro” facilities. But attention must be paid to maintain proper indoor temperatures in such facilities. The suitable indoor temperature is said to be around 15 C (or 59 F). The indoor temperature should be adjusted through ventilation. It is important to put a bonsai tree into a ”muro” chamber as late as possible and take it out as early as possible. A bonsai tree should be managed in a natural environment as much as possible. Excessive protection should be avoided.

translated by Kyodo News