I have a number of roseum elegans which get a lot of afternoon sun. Their leave are a little yellow. On the edge of a woodland area elsewhere on my property I have a larger roseum elegans which has the same yellow leaves on the sunny side - the side that is mostly in shade looks green and much healthier.

Much of the observations on yellowing on this site and elsewhare seem to revolve around the chemistry and/or the ph of the soil, but perhpas too much exposure to the sun is the answer? Could it be that I have weak stock? I am sure that there must be a bellcurve for rhodo quality?

In the interest of full disclosure I should mention that all the above rhodos were mulched with woodchips from some tree work I had done last year. Perhaps the woodchips are too new - perhaps mulching with something else would have been better? Or is it just too much sun?