Originally Posted by mikevan

Cutting the stem shorter won't harm that stem so long as it's cut above the originating point of the leaves and it's not about to flower - it'll continue growing from where you cut it. A couple or three feet is a hard cut-back - I'd go for four feet, but I've chopped mine before and had them continue growing from the center. The only time you want to really avoid cutting is when you think that a flower-stalk is coming up the center. If you cut the flower-stalk, that stem will die and you won't get nanners from it. So - younger stems can be cut back if needed, but older stems should be kept intact. Of course, it takes a lot of energy to put out new leaves and heal the wound when there are no leaves feeding the process, so don't do it often or you'll likely end up with a weaker plant and smaller bunch of nanners.

Be well,
Mike