For most long term subjects in pots I prefer to use a John Innes compost, No.3. Being loam based, it retains water and nutrients better than most others, and it's a bit heavier (so won't get blown over). Failing that, to save money, some ordinary garden soil and some compost for extra nutrients. Bamboo's not fussy (not you, Bamboo, I meant Phyllostachys and the like). Phil

Taken the proverbial out of my mouth Phil. I normally advocate loam types for long term too.

Who's taking my name in vain... Fussy, moi? I don't know what you mean, lol!

its quite a tuff old plant generaly so most garden soils will do .

you have not said which varieties of bamboo they are,some being very rampant in open,the problem being below ground with strong roots and runner traveling into places you don't want.I know this not what you asked, but forewarned is forearmed.

definatly worth knowing bis . if they are grow them behind the right membrane as there realy hard to deal with once they settle in .