Whne can I prune back bamboo (South of England) ?

[ampere]

Been grown as a reasonably effective privacy screen, in an 'estate' garden. It's about 2.5 to 3m tall and has become straggly towards the top. The whole patch is about 2m long and .5m wide, and I'd call it 'common or garden', not exotic!

Ideally I wouldn't have bamboo in any garden out of a pot but it's here now and needs looking after otherwise I get a full on view of the neighbour weeing....more or less!

When would you recommend I take the top 1m off?

[plantwoman]

bamboo shouldn't be pruned as such, but you can thin it out by removing the older canes by cutting them right down to the ground in spring.
if it looks straggly you can chop it all back and it will grow back - however you would have to put up with seeing your neighbour weeing until it grew tall enough!