Question
I have a mature copper beach tree 30ft high the leaves are being eaten by a very small whitish aphid underneath the leaf is gummy

there was a old desised apple tree growing next to it which we  removed last year

this has obversely been infected by the apple as it is the side that is most affected
the winter has not stopped the infection

it has been suggested a winter wash may help to stop the carry over    what and what time

Answer
Aphids are controlled with the use of an insecticide. Most trees are too large to spray the entire foliage so I would recommend that you treat the tree with an insecticide called Bayer Advanced Tree and Shrub Insect Control. this is applies to the soil around the tree and the roots will carry it up to the leaves and twigs and when the aphids suck the plant juices they are killed. It will take a week or so for the insecticide to reach the top of large trees. but this treatment will last the whole season. Here is a web link to this product check with your local garden type store for it. http://www.bayeradvanced.com/tree-shrub-care/products/12-month-tree-shrub-insect...