Specialty Gardening: making indoor 4-ft long counter-type planters?, 1 by cicada

cicada wrote:
Perhaps this idea will be useful to you. You will need one sheet of 3/4" plywood, 4 feet x 8 feet.

The planter is 2 feet high/deep, by 4 feet long, by 16 inches wide.

The left-over piece of plywood in the lower left corner of the image should be used as a center rib in the planter (about where the number "3" is in the image) to keep the sides from bowing out. It is the same size as the end pieces.

The interior could be coated with epoxy, or plastic sheeting, or sealed copper sheeting, or just polyurethane.