Hi there. I was wondering if anyone could offer some info regarding the wine and roses wiegela. I planted these early this summer. they are in a south-facing bed next to the house. most of the leaves have turned green, only a few at the top have some of the original purple color. what could have made them go from purple to green?

also- in the same bed, I have a forsythia that has leaves turning a yellowish color, possibly a Mg deficiency?

Any advice is appreciated!