PROBLEM TO BE SOLVED: To land-form a greening base, which has excellent water retentivity, by which the greening base having a thick layer can be land-formed and which not only is proper to the growth of plants but also can contribute to natural environment preservation and the protection, etc., of an ecosystem. SOLUTION: Coconut fibers collected from the nuts of natural coconuts are used as raw materials, a bag body 10, in which one side is opened, is formed while field generated soil and various admixtures are mixed and agitated and a slurry greening base material is formed, the slurry greening base material is nodulized on the basis of the agitation and mixing of a second nodulizing agent, and the bag body 10 is filled with the nodulized greening base material by nodulization. A greening base 12 in thickness corresponding to the bag bodies is land-formed by closing the openings of the bag bodies 10 while arranging and holding the bag bodies along a slope.
