Primary propagation for bryum can be achieved through spore sowing and division. Key success factors include ensuring high humidity, constant moisture, and indirect light, as well as preferring a slightly acidic soil type. Special considerations for bryum involve its small size and need for a stable micro-environment. Bryum propagation is generally considered moderate in difficulty due to these requirements. To propagate bryum, perform the following steps: 1) Harvest spores or gently divide clumps during damp conditions, 2) Sow spores on moistened, acidic peat or place divisions onto similar substrate, 3) Ensure consistent humidity by covering with plastic, 4) Maintain indirect light and stable, cool temperatures, 5) Allow colonies to establish before transplanting. Success requires patience and careful attention to environmental factors.