what is the variety? maybe a bit limited on root space. might just have to get what you can off it now. i usually put 2 in a 30 liter tree pot but one always seems weaker than it's partner. so i'm just going to plant each one separately next year. yours looks very dark green, maybe ease of on any nutrients and let it metabolize what its got. i don't feed mine a huge amount because i don't want to taint the taste at all. still learning myself though.