I have green fly on the leaves of my cherry tree and on 2 of my apple trees I have a white sticky mess, looks like cotton wool. I have been spraying with washing up liquid. What can I do while I am waiting for birds to clear them up? Please help.
I'm always slightly concerned when people use washing-up liquid to kill insects as it can be hit or miss. Try my Plant Invigorator, which is used by over 500 nurseries around Europe, and sorts out pests within 24 hours.
As you mention, another way to control greenfly is to encourage birds to eat them. To attract birds into your garden, hang bird feeders in the trees. After eating the feed, the birds will hoover up any garden pests.