PURPOSE: To obtain artificial soil capable of planting trees on the roof of a building, a verandah or balcony, etc., and simultaneously regulating the load within the range of the limited live load specified by the Building Standard Law and remarkably reducing the frequency and amount of irrigation and a method for planting execution.

CONSTITUTION: A waterproof mat 9 is laid on a base 8 of concrete or concrete mortar finish and a platy member 10 having unevennesses is then laid on the waterproof mat 9. Nonwoven fabric 11 is subsequently laid on the platy member 10. Artificial soil prepared by mixing inorganic ceramics obtained by converting naturally occurring zeolite into ceramics with an inorganic material and an organic material and regulating the specific gravity to 0.40-0.55 is charged onto the nonwoven fabric 11. Trees are then planted simultaneously or after the charging to create a tree planting garden 1 on the roof of a building. When the base 8 is a mortar finish of protected with a waterproof layer, the waterproof mat 9 may be omitted.