Photinia Red Robin Standard Tree
In early 2011 I planted three Photinia Red Robin Standard Trees from containers and they did extremly well throughout the year. In January 2012 one of the trees started to drop its leaves and I noticed that the leaves on the tree were a paler green than the leaves on the other two trees. The falling leaves showed no sign of disease. The three trees are planted in similar situations but the sick tree is close to limestone chippings. Could the soil, which is normally neutral, have become alkaline from the limestone chippings and be the cause of the problem? If it is what can I do to rectify the soil after I have removed the chippings?