PROBLEM TO BE SOLVED: To provide a block for growing moss which can be easily disposed on a rooftop surface and is suitable for growing moss.SOLUTION: The moss growing block 1 is produced by press-forming a cement composition which is obtained by admixing crushed stone 12 composed of at least either one of the group consisting of roof tile, perlite, plaster, blast-furnace water-granulated slag and foam glass, sand 13 and low-alkaline cement 14 containing aluminum oxide together to form the composition into an oblong plate state having a recessed part 11 on its top surface. The moss growing block 1 is placed on the rooftop surface in juxtaposition with other ones without being fixed to the surface, and a moss vegetative base is disposed in the recessed part 11 of the moss-growing block 1.【課題】屋上面への配置が容易であり、苔の育成に適した苔育成用ブロックを提供する。【解決手段】瓦材、パーライト、石膏、高炉水砕スラグ及び発泡ガラスからなる群の少なくともいずれか一つにより構成した砕石１２や砂１３及び酸化アルミニウムを含む低アルカリ性であるセメント１４を混合したセメント組成物を加圧成型して、上面に凹部１１を有する矩形の皿状に形成した苔育成用ブロック１であり、苔育成用ブロック１を屋上面に固着せずに並置し苔育成用ブロック１の凹部１１内に苔植生基盤を配置している。【選択図】図２
