Phyllostachys Nigra Bamboo dying?

bamboo is crazy tough even vs weedkillers. just a waiting game till it returns. you want dead canes for garden uses anyway. just be careful to wear gloves when harvesting as many bamboos have little needles around the leaf joints

 

@Kate1984 whereabouts in the country is your garden?
Dry winds are not good for bamboos, mine suffers in the wind.
The other thing is given the dry hot summer did you water your bamboo at all.
Next year in spring I'd feed with blood, fish and bone and then if we get a dry spell then water thoroughly say once a month.