Fill the planting container completely with potting soil for herb containers.
Insert the awl into the PVC pipe and tap it with a mallet to make a hole. Repeat creating holes up the sides of the PVC pipe on all sides to allow water to flow through the holes.
Push the PVC pipe 4 inches deep into the soil in the center of the planting container.
Insert the wooden stakes at opposite sides around the edge of the planting container.
Push the stakes in far enough so their tops are even with the top of the PVC pipe.
Staple the chicken wire around the wooden stakes.
Line the inside of the chicken wire with sphagnum moss. Hold the moss against the wire with one hand while filling behind it with potting soil.
Push the parsley and viola seeds through the holes in the chicken wire into the soil.
Pour water into the PVC pipe in the center and into the soil at the top of the tower until the soil is slightly moist. As the plants grow, they will emerge out the sides of the tower, through the holes in the chicken wire. Pick the parsley and viola flowers as needed for cooking.