The utility model relates to a cave planting pipe, which comprises a pipe body with a wide upper part and a narrow lower part, the top end and the bottom end of which are respectively provided with an opening for the root system of plants to penetrate； the outer side of the pipe body is radially concave, and a plurality of protruding ribs are formed on the inner side of the pipe body, each rib extends along the height direction of the pipe body, and on the inner side of the pipe body, each rib forms a relatively concave guide groove between them, so as to The tube is made of polylactic acid, which can be decomposed naturally and is easy to be transplanted.一種穴植管，包括有一上寬下窄的管體，其頂端及底端分別設有一開口以供植物的根系穿設；管體的外側面徑向凹入而在管體之內側面形成複數個突出狀的肋條，各肋條沿該管體之高度方向延伸，於管體之內側面上，各肋條之間分別形成有一相對凹入的引導槽，俾供容置植物根系並引導其在槽內空間延伸生長，以及該管體以聚乳酸材質製成，可被自然分解而易於移植植物。
