1. A device for cultivating underlying material around a fixed object of a predetermined diameter including: a handle rotatable in a circular direction about a vertical axis; a mounting plate connected to and extending laterally from a lower end of said handle; inner and outer vertical cylinders attached to said mounting plate concentric with said vertical axis, said inner cylinder having a diameter greater than said predetermined diameter of said fixed object; a plurality of circumferentially spaced flattened vertical cultivating blades positioned on said mounting plate between said inner and outer cylinders, each of said cultivating blades defining and lying in a plane parallel to said vertical axis and oblique relative to said circular direction and to the radially adjacent portions of said cylinders and having bottom edge means for scraping the underlying material, with said inner and outer vertical cylinders terminating in bottom cutting edges in substantial lateral alignment with said bottom edge means of said cultivating blades; and a horizontal plate member between said inner and outer vertical cylinders having access slots which allow passage of said cultivating blades respectively for cleaning any underlying material stuck between said cylinders and being movable from a normally lowered position adjacent said bottom cutting edges of said cylinders and said bottom edge means of said cultivating blades to a raised position adjacent saId mounting plate.