Create a terrarium: First steps
1. Select plants for your terrarium. Dwarf and slow-growing plants that thrive in warm, moist air work best. Plants with different heights, shapes and textures add interest.
2. Gather ornamental accessories. Small pebbles can resemble rocks and boulders; small branches and moss give your garden a natural look.
3. Choose a clear container large enough to hold the plants you want to enclose. Wash it thoroughly.
4. Put down a layer of drainage material, such as pea gravel. Depending on the size of your container, you'll need about a half-inch to 3 inches of pea gravel.
5. Sprinkle with fine charcoal (generally available at garden centers), which absorbs gasses and chemicals.
6. Layer 2 to 6 inches of a sterile peat-based potting mix over the base.