Build the frame for the piece of garden wall art using the wire mesh. Using the wire snips, cut two pieces of wire mesh in the shape of 1-foot by 1-foot squares. Place one square of wire mesh on the ground. Spread a 1-foot by 1-foot square sheet of black plastic cut from the trash bag on top so that the edges of the wire and plastic are evenly aligned.
Distribute a thick layer of wet sphagnum peat moss across the entire sheet of plastic in an even manner and pack firmly into place by hand. Spread enough of the sphagnum moss so that it is at least 2 inches thick after being packed into place. The sphagnum moss will serve as the rooting medium in which the plants will establish themselves and from which they will draw nutrients and water. Pack enough sphagnum moss into place to provide sufficient material in which to hold and grow small succulent plants.
Spread an even layer of moist potting soil about 1-inch deep over the top of the packed sphagnum peat moss. Evenly distribute 2 tablespoons of time-release plant food such as Osmocote over the potting soil.
Cover the potting soil and time-release plant food evenly with a layer of sphagnum moss, about 4 inches thick. Place the second 1-foot by 1-foot square of wire mesh on top of the layer of sphagnum moss. Press the square of wire mesh down firmly to compact the layers of sphagnum moss, potting soil and time-release plant food and attach to the other square of wire mesh using lengths of bailing wire.
Insert the succulent plants into the sphagnum moss so that when you are finished nothing but succulents will show and little to no wire mesh framework will show. Use a screwdriver to burrow holes in the sphagnum moss and then slide the succulent stem into the hole. Pack additional sphagnum moss around the plant stem if necessary to help hold the plant in place.