The problem with fabric Grow pots are mold build up and root rot from the fabric staying wet The Wet material does not allow air to pass very freely. Our special mesh allows for better drainage than traditional grow bags. Rain Science Grow bags provide More stable root zone temperatures, Greatly improved drainage through the entire growbag and extra oxygen to the soil because of improved air flow through the fabric. This air flow facilitates a process called air root pruning, where the plant creates a bunch of tiny feeder roots which are better at absorbing nutirents, this in turn leads to increased plant growth.