Black bamboo - how to stop it drooping?

I planted a black bamboo (Phyllostachys Nigra) about 2 years ago. As it has grown the culms seem to have problems staying upright - please see attached photo.


This is particularly evident during wet weather.

Would you recommend I stake the bamboo?

 

This is caused by the weight of water on the leaves and is normal
You could stake it or tie it back to the fence if you like
Bamboo does not thicken out as it grows. A culm will always stay the same thickness as when it first appears. Culms will gradually thicken as the root system develops. If the culms are too thin then you can always cut them off to encourage thicker culms to grow

 

Thanks very much for the useful advice. I think I'll try to stake/tie them in the first instance.