From our perspective as plants, the most critical concept for you to understand is that most popular orchids, like Phalaenopsis and Cattleya, are epiphytes. This means we do not grow in soil in our natural habitat. Instead, we anchor ourselves onto the bark of trees high in the canopy. Our roots are exposed to air, light, and frequent rain that drains away instantly. A traditional soil mix would suffocate our roots, retaining far too much water and causing them to rot. Therefore, a proper potting mix for us must replicate these airy, well-draining conditions, providing support while allowing our roots to breathe.
The simplest and most effective potting mix for a beginner to use for us is a combination of just two ingredients: coarse fir or pine bark and horticultural charcoal. The bark chunks are the primary component, making up about 70-80% of the mix. They provide the chunky, open structure that allows for excellent air circulation around our roots and mimics our natural anchor on tree bark. The remaining 20-30% should be horticultural charcoal. This component is not fertilizer; its job is to absorb impurities and toxins from the water, keeping the mix "sweet" and preventing it from becoming sour over time, which is detrimental to our root health.
For a beginner repotting a single Phalaenopsis orchid, a straightforward recipe is best. You will need 4 parts of medium-grade orchid bark (pieces about ½ to 1 inch in size) and 1 part of horticultural charcoal (pieces of a similar size). Simply combine these two components in a bucket and mix them thoroughly with your hands. There is no need to add soil, peat moss, or sand. Before you pot us, please soak the bark mix in a bucket of water for about an hour. This makes it easier for our roots to adjust to their new home, as dry bark can initially repel water.
When you begin repotting, handle our roots with great care. Gently remove all of the old potting medium, carefully untangling the roots. Use sterilized scissors to trim away any roots that are black, mushy, or papery-dry; healthy roots should be firm and silvery-green or white. Position us in the new pot so that the base of our lowest leaf is just at the top of the potting mix. Then, gently fill in around our roots with your new pre-moistened mix. Do not pack it down tightly—our roots need those air pockets! A gentle tap on the pot helps settle the mix without compacting it. Wait about a week before resuming your normal watering routine to allow any disturbed roots to heal.
