A plant cultivation solid medium for potting a plant includes a water retention block body (2). The water retention block body (2) has a top surface (23), a plant-receiving chamber (213) that is indented from the top surface (23) and formed with a top opening in the top surface (23), a bottom surface (24) opposite to the top surface (23), and an air chamber (221) indented from the bottom surface (24) and formed with a bottom opening (223) in the bottom surface (24). The bottom opening (223) has a cross-sectional dimension greater than that of the top opening (214).一種植物培育用基質塊，包含一保水性基質單元。保水性基質單元形成一具有一個上開口並用來容置一植物的容置室，以及一與該容置室呈上下設置且具有一個下開口的氣室，且該氣室的下開口的尺寸大於該容置室的上開口的尺寸。該植物培育用基質塊為預先成型，植物可直接栽種在該容置室中，所以具有操作方便及省時的效果。同時該植物培育用基質塊具有良好的吸水性及保水性，並透過該氣室能避免當植物培育用基質塊因含有大量水分而發霉的問題。
