

Nice response. It is so strange the conventional ‘wisdom’ around bamboo. And it’s usually people with no actual experience with the plant.
I mean, you clearly mentioned they are in containers (which incidentally may be the reason the culms aren’t expanding fully, few bamboos do well in containers and balcony conditions can be very harsh). I swear people think that it will crawl out and take over your town overnight.
Sounds about ideal! Even the clumpers like to have all the room they can get. I’ve been able to get phyllostachys nigra to grow well in larger containers, giving them ample room and excellent soil prep as you describe.
Good luck! I love bamboo