Paphiopedilum is a group of orchids better known as lady slippers. While there are many paphiopedilum varieties, in general they need bright light, warm temperatures, moist soil and regular fertilizing. They also need to be repotted on occasion. Keep a few things in mind when repotting your paphiopedilum to grow a successful, blooming plant.
When to Repot
Wait until your paphiopedilum has finished blooming to repot it. Flowering can happen any time of the year and one plant can produce several blooms. Each bloom can last for one to three months. Cut off the flowering stems at the bottom when they fade and when no more arise, it's time to repot.
Repot at least once every 12 to 18 months. This will encourage your paphiopedilum to grow and bloom more. Signs that your plant needs repotting: the soil holds moisture longer than usual; roots are growing near the soil's surface (sometimes visible); the bark begins to strip and break; and the roots are root bound (look out the drainage holes for extending roots or up along the sides).
After you take your paphiopedilum out of its current container, gently shake the soil away from the roots. Then cut off the roots that are dead or rotting. This is also the ideal time to divide large paphiopedilum if desired, but since this is a delicate process, you may want to take your plant to a nursery for them to do it.
Use potting soil labeled for orchids, or a potting mix with well-draining elements such as fir bark, coconut husk chips or sphagnum moss. Then replant your paphiopedilum into the next size pot (roots should fit inside the pot comfortably). Spread the roots out and work the soil in between the roots. Plant to the same depth as it was previously planted.