PROBLEM TO BE SOLVED: To provide a foundation bed for planting with which a burden to a building is slight, and a tree, etc. can be planted, and which provides excellent application workability and a connection means, etc., against a strong wind on a rooftop, and to provide a method for greening a rooftop. SOLUTION: This foundation bed for planting is characterized in that the foundation bed is a thick, square foundation bed provided with continuous void parts formed by partial fixation of lightweight coarse aggregate to each other with a cement mortar, notches reaching a fixed depth from the top toward the bottom are formed at four corners of the foundation bed, and the continuous void parts of the foundation bed are packed with soil for planting. This method for greening comprises arranging and installing a plurality of lines of the foundation beds for planting on a waterproof layer formed on a concrete slab of a building, using the foundation beds for planting for direct planting of lawn, flowering plants, etc., and utilizing at least one vertical hole formed by notches of the adjacent foundation beds for planting of low tree and/or for fixing the adjacent foundation beds to each other.
