The name 'ericaceous' comes from the Latin name for heathers, Erica!
We inherited a pot with camellia some years ago and it wasn't doing very well...
...so this year we took the plant out altogether and replaced the old compost with this one:
...and a 'miracle' happened as promised on the bag (ha, ha)...
We also fed the plant with a special 'acid-loving plants' feed for 3 months and it looks amazing now. No yellow leaf in site!
So worth the time and money investment.