Kent,
United Kingdom 
Good morning, I cut down an apple tree, to about 6 ft and it has now sprouted over the past year to about 12' I am not worried about getting apples on it, but it gets very diseased quickly, a. when can I spray it and what with, b. when can I prune it hard. thanking you in anticpation
19 Jan, 2011
Answers
And that will also help any sprays to penetrate the tangle. Once pruned. I would spray with lime-sulfur to kill any disease spores trying to overwinter on the bark. Spraying with soap and vegetable oil before will also scotch most insect eggs and pupae.
19 Jan, 2011
Previous question
You can still hard prune now, why not take off all the growth that is not really needed and create a nice framework of branches, and any shoots through the summer nip off and aim for an open centre so the air can circulate which could help with desease.
19 Jan, 2011