Abstract: A device and method for composting comprise an assembly of stackable rectangular double walled plastic sub-units. Each sub-unit has four panels which are engaged in an interlocking relationship. Each sub-unit has a plurality of protrusions extending from its top edge, and protrusion-receiving recesses in its bottom edge for receiving the protrusions from an adjacent sub-unit. The composter has a lid with a peripheral ridge on its under side for securely fitting around the top edge protrusions of the uppermost sub-unit. The lid has two half-portions which are centrally attached in a hinged relationship so as to allow opening half of the lid while the other half remains closed.