Ask-a-Dave's-Gardener: Very unhappy Rhododendron Red Jack, 3 by shinysun

shinysun wrote:
I have a Red Jack and a Nova Zembla next to each other, bought 3 years ago, fine last 2 years but this year the Red Jack looks decidedly like it\'s about to give up!

SW UK - so very wet winter/early spring followed by 6 weeks sunshine during which I noticed the leaves at the back withering and a lot of other ones going yellow.

Went for drought as that fit the current weather conditions and started watering daily until it got much cooler/wetter through June - and plant looks even worse!

NE facing so sun morning thru early PM. In spring gave handful of ericaceous plant food and compost mulch.

Any other ideas? You can see the Red Jack on left and Nova Zembla next to it. in last pic.