I've got a beatiful bunch of bamboos (2.5m tall) replanted to my garden 6 months ago. It had grown nicely for years in my old and new gardens until recently. The leaves suddenly started to turn yellow one month ago, and now half of them became yellow. It is obviously dying. I am desperately trying to save them. Is there anyone who can help? Is it possible that it is affected by neighbours' plants or weedkiller? Many thanks for any advice.