Bamboo looking a bit rough ....

Planted some mini bamboo in a big pot a few years ago and the year before last decided to split to make two ... last year it looked a bit rough but this year it is worse - the other pot is terrible. I thought bamboo was classed as a weed in the far east and would grow anywhere!! ... but this stuff has turned a bit naff. I must have done something wrong - any ideas anyone

Thanks in advance

 

Bamboo in a pot does tend to struggle.

What sort of soil is it in?

Can you not try some in the ground?
It will be much happier.

If not, take this plant out the pot, and take off as much of the existing soil as you can. Then repot in a loam based soil and top dress with an inch or two of manure.
Give plenty of water, particularly when the weather is warmer...if that ever happens

You can also trim out the thinner culms, and the culms with no leaves on them.