What is causing my holly to go bald in one specific area?

Steveandaly

This well established holly looks fine at the front (picture 1) but is suffering from die back towards the top at the rear of the bush. The impact is on the east facing side, is about 2 feet square and about 5-7 feet high (picture 2). The rest of the bush appears healthy. The wildlife in my garden, particularly the birds, love the bush so I would hate to lose it. Any ideas what is causing this and how I can help the bush to recover?
Steve, Hampshire

Obelixx

It may be holly leaf blight which is a fungal disease.  It can be particularly infectious in damp weather.   You need to remove all affected stems as close to the main stem as possible and then burn them or put them in the council bin, not the green waste, so they can't spread elsewhere.

Keep an eye out for any further stems losing their leaves and remove immediately to try and control it.   I would also suggest giving it a good feed this spring with some slow release fertiliser and an instant tonic of liquid seaweed to help strengthen it.

https://www.rhs.org.uk/advice/profile?pid=175 for more info.