Posted: 22/07/2015 at 20:22
Thank you that's all very helpful advice!
I'll cut down on the feeding in that case! It has just been in this pot for a year but has produced at least 10 new canes this spring/summer so could well be pot bound and need dividing or replenishing.
The garden is very windy and the pot has blown over a few times this year so some of the damage might be wind burn too I guess?