Hey fellow growmies 👋, so my girls are doing ...

not too big of a deal.. either getting a bit corky or it is trying to pop some roots - could be genetic or environmental if moist and dark there. the corky trunk is a symptom of .. let e get my leaf chart out... a Boron def can cause it... but it'd be rare to have a trace element deficiency in soil... and is that a "hydro" line of nute products? those would have all the trace elements in abundance if decent. So, i'd check your pH of runoff and what you feed, just in case... if that is all good and you aren't getting teh trunk wet often, i'd chalk this up to genetics or something else you can't control. I've got this on a plant or two right now... they are very healthy otherwsie. The trunk is dry and not covered up from light, so it's probably genetic or somethign i cannot control.. the key is the plant is perfectly fine, otherwise (for many weeks).