Line the sides of the bottom half of the glass cylinder with sheet moss so the moss is facing outward. While holding the sheet moss in place, fill the bottom of your container with about 1" of pea gravel. Next, add a thin layer of gardening charcoal on top of the pea gravel. (This is great for containers without drainage holes because the charcoal absorbs excess moisture.) Finally, fill the cylinder with moistened potting soil until it's an inch below the top of the sheet-moss lining.