PROBLEM TO BE SOLVED: To obtain a lightweight greening material based on a vegetational material prepared by vacuum sucking fallen leaves in surface layers on fields and mountains or surface layer soil containing the fallen leaves and fallen seeds. SOLUTION: Fallen leaves 1 in surface layers on fields and mountains or surface layer soil containing the fallen leaves 1 is loosened and the loosened fallen leaves 1 or the surface layer soil containing the fallen leaves 1 and fallen seeds (a) contained therein are used as a vegetational material 2, which is then sucked and collected with a vacuum. The collected vegetational material 2 as a base is mixed with at least one of a soil conditioner, a water holding material and a fertilizer to afford a lightweight greening material 4.
