i have a black bamboo and it is growing green canes do i have to prune them out or will they turn black thanks dave

They will go black with age.
I trim all the lower leaves off of mine up to about 3ft to show off the stems, as well as cutting off at soil level any really skinny ones that come up as they dont get much fatter and the energy can go into producing stronger ones.

I have photos of it on my page.

when do you take out the skinny stems and remove the lower leaves Treesandthings please...:>)

I take out the skinny stems when they are about 6-12" tall and Ive realised they are going to be skinny.

As for the leaves once the stems are a couple of feet tall I start taking the lower leaves off.

The new first years growth is green but will blacken over the next year or two. Nothings wrong