weetbix456 wrote:That colour variation on the nothofagus cuninghamii is a result of new growth as far as I am aware
Second this. I believe it's a way of the plant not overusing delicate new growth if that growth is in a sunnier place. Sunscreen if you like. I've seen whole Myrtles in January/February that are coloured red-yellow when in an exposed spot. The leaves are really soft too, not as tough as the older growth. I have seen this colouration in other alive plants too, even some tea-trees.
I would love to be looking at fagus right now! Alas.