Well, people differ in what media will be in the bag, everything from potting soil, coir, perlite, and other media are used. I personally prefer sterile coarse or super coarse perlite. The main two things that bagging does for you is it controls moisture long term and it also is pretty much bag, seal, and forget it. Because you can't bag root in the "toasty" temperatures that we can here in SE Florida, I would suggest that you purchase a nice, large heating pad to place those bags on.
