Well not burning your house down is a basic rule in growing.

Stinky is the soil wizard here.....she's the one that taught me that you should have a gallon of soil per foot of stem......and yes I do think that this your problem and a transplant into larger containers will help.....if not solve....the issue.

Plants need root room.......and if your roots aint happy your plant aint happy......it's easy to forget them since they aren't what you look at in a plant but believe me they are the MOST important of all.

Treat them nicely.