I have read so many, many times that it is good to put coarse material in the bottom of a pot to help drainage, and recently I have been reading the opposite. I must say it just seems to make sense that coarse materials drain better, I can't seem to wrap my brain around how using coarse material hinders drainage. To me the new version may actually be stating to simply use coarse materials in your potted plants, and not finer materials on the top layer, if you are having any drainage problems.
