Soak Gemma pumice stones in water for a few minutes. Put some stones in the bottom of the vase. You'll want at least 2" of stone in the bottom, then the roots, and orchid leaves situated at the top. When you have some stones in the bottom, position the orchid where you want it, and fill in and around the roots with stones. If you prefer sphagnum moss around the roots, use this now instead of pumice stones.