From my perspective as an orchid, the medium you plant me in defines my entire world. It's not just a pot of dirt; it's my home, my water reservoir, and my air supply. The fundamental difference between moss and bark lies in their water retention and aeration properties. Sphagnum moss acts like a dense, water-absorbent sponge. It holds a significant amount of water close to my roots for a long time. Bark, typically made from fir or pine, is the opposite. The chunks create large air pockets and drain very quickly, holding much less moisture around my velamen (the spongy root coating that absorbs water).
My watering needs are dictated by how my roots interact with these mediums. In bark, water flows through quickly, wetting the roots but not saturating them for long. I can drink my fill during the watering, and then the environment becomes airy again, which my roots love because they also need to breathe. In moss, the hydration is a slow, prolonged event. The moss absorbs the water and releases it to my roots gradually. This means I have constant access to moisture, but the danger is that my roots can be suffocated if the moss remains too wet for too long, preventing crucial oxygen from reaching them.
Please do not water me on a rigid schedule. My thirst depends on light, temperature, and humidity. You must check the conditions in my pot. For bark, the signal is clear: wait until the pot feels very light and the bark is completely dry. You can also stick your finger or a wooden skewer into the medium; if it comes out dry, I am ready for a drink. For moss, the test is different. You must feel the weight of the pot and press the moss with your finger. I need water when the top inch feels dry and the pot is noticeably lighter, but the moss in the center should still feel slightly cool and damp, not bone dry or sopping wet.
The method is just as important as the timing. For both mediums, I prefer thorough hydration. Take my potted self to the sink and run lukewarm water through the medium for about 15-30 seconds, ensuring my roots are fully saturated. The critical step is to let all excess water drain out completely. For bark, this is fast. For moss, you must be patient. Gently press the moss around my base to squeeze out any excess water trapped in the sponge-like material. Never let my pot sit in a saucer of water; my roots will rot. The goal for moss is even moisture, not sogginess, and for bark, it's a cycle of complete drenching followed by complete drying.
