Pruning apple trees

I would not even remove dead wood at this time of year, unless the disease is spreading rapidly and the tree is in imminent danger of death, or poses a safety hazard. I suppose that you could trim back the dead wood, but not cut into live wood (to remove the last of the dead wood) until the winter.

Most pruning of apple trees should be done in winter (Nov-Feb), when the tree is dormant and the temperature is too cold for fungal spores to germinate in the pruning wounds. Winter pruning is used to boost the tree health by removing dead/diseased wood and also to invigorate the tree.

Summer pruning should only be done to the soft, young shoots as they turn from green to red-ish brown at the bases. Summer pruning is used to reduce vigour and increase flower bud formation for the following spring.

If you prune older wood in summer, it is exposed to fungal spores (which are numerous in warm weather and germinate very quickly). The spores could easily allow canker to get into the pruning cuts, which will then mean that you will have to cut out the cankers, or - even worse - the branch is cut back hard now and the canker gets into the main trunk, which is often a death sentence for an apple tree.

James Grieve is particularly vulnerable to canker and wood-rotting fungi.

HTH
FB

Thanks - I'll leave it until the winter, then.