I have a Camellia in a small inherited raised bed which it shares with a variegated laurel, 2 runnery roses (which I have cut back), a buddleia (which I have cut down) and god knows what else. The bed is only about 6 foot by four foot and everything in it is mature; I can't dig anything out at the moment, because there is a Yellowhammer nesting in there somewhere.
The Camellia leaves have started yellowing and it only had 2 flowers on it earlier in the year. I have been giving this bed a great deal of water because there's so much in there. Is it likely to be overcrowding that's affecting the Camellia or has it got some horrible disease?