My 3-year-old Victoria plum tree has been covered in brown spots; the spots then fall out leaving a lacy-looking leaf.

What is wrong and what can I do about it please?

The spotting and subsequent holing are the result of bacterial canker.

The infection enters the tree through the leaf scars left as the leaves fall, this can be reduced by spraying monthly with a suitable fungicide from mid-August to mid-October.

This year my plum tree leaves were absolutely plastered with grey aphids, and were very sticky.

Can this be prevented?

The mealy plum aphid spends the winter on the tree in the egg form.

A suitable chemical wash before the end of January will kill off the eggs and prevent early damage either from the aphids or the sticky honeydew they secrete.