Assembly kit for a holder for growth supporting medium

A kit to assemble into at least one holder for a growth supporting medium such as soil, said kit comprising a backing member and two posts to be erected in vertical parallel spaced relationship against said backing member, first coupling means on each post spaced apart at regular intervals along the posts, at least one contoured front panel having an upper edge and a lower edge which is shorter than the upper edge, said front panel having a central portion disposed between two end portions, second coupling means on each of said end portions to respectively releasably engage with the first coupling means on the posts to position said end portions in planes at right angles to the plane of the backing member fixed to the cooperating post and to space said central portion from the backing member, said central portion and end portions of the front panel and the backing member providing encircling walls for a soil zone which is open top and bottom and has a smaller cross-sectional area adjacent the front panel lower edge than it has adjacent the front panel upper edge and a bottom panel to close off the bottom of a selected soil zone.