Posted: 19/08/2013 at 11:16
I think it was the lime from the farm: you just have to see the affect of salt spray from winter roads that brown Yew.
I have a Yew in my clay soil, though I improved the drainage somewhat and it was in a pot for years before - it was not getting enough water and nutrients in the pot. It turned dark green from almost yellow within weeks.
I would be tempted to add an ericacious liqduid feed and a high nitrogen feed.