The first thing I want to know is how much you are planning to cut out, and how big and old the specimen is - with most kinds you do not want to do a lot of volume reduction to a mature tree, regardless of the time of year. Otherwise, yes, maples may bleed when pruned during the winter - the time when this could be expected to be the worst would presumably be the same period as when sugar maples might be tapped. November might be too early in the season for much bleeding, and it wouldn't be expected to hurt the tree anyway. Unless there is going to be so much cutting that a whole bunch of sap comes out. But again there the main problem will be the amount of wood and potential foliage that is taken away, rather then the bleeding. It always depends on the specific details involved but in general if a tree looks quite dramatically different after pruning it has been pruned too much.

Your tree should have it's main late rial root just below the ground surface. It should not be mounded up as they have done. Only a couple inches of mulch is needed. Your soil should not be amended. As the roots grow out they will do best conforming to you natural soil providing it is not all clay. Fertilize only lightly in the spring. You might use a little "Superthirve" to reduce any shock. Trim out your top branches but leave the lower for now. This will allow the upper and inside bare spots to get more sun and fill in over time. May not look the best for a little while but your best plan of action. If you decide to remove any lower branches, any major trimming should be done when the tree is dormant, early spring or fall. Do not trim in the heat of the summer! There is still time to form your tree. Just look at it as a big Bonsai and look long, hard and from all directions about what branches you wish to remove before cutting. Seal all cuts over 1/2 inch to reduce bleeding and protect from disease. Good luck, Grancru

Your tree looks great there is no right or wrong form of JM..that being said ( to may make mowing easier) i would cut off all the vertical very low branches ( two on right one on left) As well as any other lower ones that seem to be ( but it's hard to tell ) ;>) coming out in mass along with a much larger branch or where a branch that was cut ...just keep the biggest one in a branch forest. Otherwise i wouldn't mess with it ... I have no idea where you be from but if still cold there and dormant you'd better get going if you want to do it now ...or wait til next fall after leaf drop David

jmg1717, the ultimate choice to prune or not to prune is yours :-) Your post has garnered a number of differing opinions, including several from folks extremely familiar with growing these trees and their particular habits. With Japanese maples. most pruning decisions are going to be personal - there are simply no hard and fast rules about their pruning and all decisions should be made on a case by case basis. You seem to be assigning a lot of weight to the opinion of your landscape architect. I would just comment that because JM's do not develop a distinct leader, there is no apically dominant growth point in the tree, but all branch tips will share in apical growth. Removing the branch(s) in question will not necessarily cause the tree to grow taller faster but could very well produce increased overall growth of the canopy......there IS a difference :-) Also you want to be cautious with heavy pruning very late into the winter. Sap begins to move quite early with JM's and pruning after about mid-December may create a lot of bleeding. btw, although not necessarily obvious with this format, there are individuals that post here with some equally impressive credentials. Mike (miketann) is an extremely knowledgeable landscaper (now retired) with many years of experience and an entire personal "forest" of JM's :-) I too have a degree in horticulture and many years experience as a landscape designer and a nurseryperson. Just saying you are getting the benefit of a lot of years of professional experience on this forum as well.