Why has my Camellia gone yellow?

Plants such as Rhododendron, Azalea, Camellia and Acers are often described as ‘ericaceous’, indicating that they thrive in an acid soil.  In fact, it is more accurate to say that these plants do not thrive in an alkaline soil, they are perfectly happy in a neutral soil especially if iron is added.  Here is the explanation: ericaceous plants cannot...