A customer of mine wants me to prune back some birches which are in their carpark. I have read up on this in my RHS book and it says late winter/early spring, with some able to be done in late summer to early autumn referrring to the sap bleeding that may take place if relevant to the particular group.
By the looks of things they want fairly severe pruning as the trees are 'obstructing the views from the lower floor'!! I think they are completely mad as this will result in lovely 16-18 ft trees being reduced by around 6-8ft, but I may be wrong!

Could someone please throw some more light on this regarding both the pruning time and severity and what result this will have on the health of the trees and their size and quality following this action. Any assistance and time afforded to this is very much appreciated as I would be very keen on not causing long term damage to such wonderful young trees. Thank you. Terry Deans