after having transplanted a plant to any size pot after about a week or so some quick roots will peak through the bottom of the pot. It 's does not mean there is no space left and that it's rootbound!They go for water and water goes to the botom. after a couple weeks of being in big pots and the saucers have dried in between feedings a couple times they usually go back in the pot! Some growers get rid of the excess water in the saucers and barely ever see roots popping out. No water no roots!