Originally Posted by echinosum

Given that bamboos are propagated from divisions, the idea of digging them up and growing them in a pot temporarily is quite usual for bamboo, although some kinds resent it, that doesn't apply to any of the ones you mention. This isn't the best time of year for it, because there will be new culms forming which have not matured yet. If you could delay until at least mid August, that would be better. Spring and early autumn are the usual plant operation periods for bamboo.

In digging them up, you will lose many of the fine roots, whcih are feeding the plant. So you need to reduce the quantity of plant they have to support, either by shortening the culms or thinning them out. If you have to do it now, not later, maybe you should just get rid of all the culms whihc have shot and not matured yet, they are probably going to abort. Although given that you have just planted them recently out of fairly small pots, maybe you can get pretty much the whole plant out, fine roots and all, if you provide it with a generous rootball, and maybe they will be barely set back at all.

Especially at this time of year, make sure they are well watered and the planting medium is rich. Include a little sand in the potting medium, as bamboo takes up silica. Put them in rather bigger pots than you took them out of in the spring.