I planted a row of so-called grafted 'evergreen' ornamental pear trees in February this year. Over Winter a few leaves turned /yelloworange/red and dropped off. But in the last three weeks a great many of the leaves have developed a darkbrown/black rim, then change colour and drop off. Are my trees not so evergreen afterall? or is it a disease or fungus? There is lots of new growth happening, leaves, shoots and flowers (as we have had a spot of mild weather in Melbourne). I am worried that the new leaves might become effected, if it is disease. Should I be doing something urgently to fix this? The top foot of each tree had it's leaves and shoots chewed off by possums a while back. Not sure if this would have caused it?
http://i562.photobucket.com/albums/ss69/sierra_099/IMG_0620.jpg
http://i562.photobucket.com/albums/ss69/sierra_099/IMG_0622.jpg