Coconut fiber or coir is found in pet stores, I'm told. I recently got some blocks at Costco of all places (see pic below). I planted all my adeniums in half coconut coir chunks and half potting soil. It drains really well. I also have purchased the fiber from Western Farm Service in Oxnard by the bale, but I prefer the chips to the fiber. It did not, however, dry out fast enough for my AeAe's, which died in it, but that was probably my fault for watering too much. It should be rinsed prior to use to avoid any salt.
