Poplar tree problem
Zelma Stoffberg of Onrus River writes About six years ago, we planted a few Populus simonii trees on our property. They started off well but we noticed problems about three years ago. The trees sprout well in spring but by December the underside of the foliage (right in the photo of the leaves) starts developing an orange-brown powder and this powder spreads throughout the garden. The upper surface of the leaves (left in the photo) is covered in spots. The leaves soon die and fall off. Our local nursery suggested we spray with Virikop, but this has not helped over the past two years. In summer, our trees look so sad and provide no shade at all (below left).
JJ replies One of your problems is indeed rust and the other could also be a fungus called shot hole disease (not to be confused with the shot hole borer). Virikop is a good fungicide but is unfortunately not systemic. I recommend Tenazole, a systemic fungicide that can be applied again after two weeks – it is absorbed by the tree and heals it from within. Feed your trees regularly with 7:1:3 to encourage new foliage – a healthy tree also has more resistance to diseases. >>