To provide a root cutting fertilizer for flower pots which can easily cut old roots of planting trees filled inside a flowerpot.SOLUTION: The cylindrical shape has an end face of a shape cut in a direction perpendicular to the cylinder, the end face side is an upper end face, the other end of the cylinder has an end face cut obliquely, Wherein the end face side is a lower end face and the lower end face is sharply pointed.(FIG.【課題】植木鉢の内部に充満した植木の古い根を容易に切り取ることができる植木鉢用根切り施肥具を提供する。【解決手段】円筒形であって、該円筒と直角方向に切断した形状の端面を有し、該端面側を上部端面とし、該円筒の他端は斜めに切断した形状の端面を有し、該端面側を下部端面とし、該下部端面を鋭利に尖らせたことを特徴とする植木鉢用根切り施肥具。【選択図】図3