If it possible to slide the root ball out without damaging anything? If so, look at it and see if it looks like it needs a transplanting. Depending on the environment, they could need transplanting anytime b/w a couple weeks to a month. It's all really dependent on how fast your root system is growing. Just make sure to mix at least 1/3 perlite to the mix. If it's topsoil then maybe you should mix about 1/2. I like a lot of perlite as to I'd rather be giving my plants watering more often to give them fresh oxygenated water compared to something that takes a week to dry before needing water.