Surrey, United Kingdom

Hi, I have 3 rhododendrons in my garden, which have been in situ at least 10 years. 2 are in the borders and look healthy with dark green leaves and flower well. The 3rd one flowers ok, but is in a large bed in the middle of the garden where I understand there used to be a line of trees many years ago. The leaves have become pale and yellowy and it doesnt appear to have grown in the 7 years I have lived here. What could be the cause of the yellowing leaves and how can I green it up please

• 2 Oct, 2010