Wow, what a journey! I would chop it right above that bottom layer of leaves that are just above where it splits, and keep the very slightly higher left end of the bunch. Of course you'll also be including those two leaves at the bottom in back. In other words, make the cuts unequal, slanting from above the downward pointing leaf facing the inner curve at the nebari, and include those above it on the other side over the outside curve. I'm basically just going by the last picture here. You might want to see how well it responds to leaf stem cutting of the bottom leaves no-later-than-now this season, if you do end up with smaller ones (hopefully!), but then not do it again until some time far in the future.

I would wait until winter before greatly reducing the two long shoots. Maples should always be pruned in winter while the tree is dormant. Otherwise you risk the chance that it will bleed to death.

In spring, before the buds burst, place the tree back in a much deeper pot so that the nebari is completely covered. The roots really need to develop more. Maybe you could make some tiny scratches in order to promote root-development on places where you would like more roots to form.

You have a gnome hole 'feature' you can use to your advantage, and an ugly scar that is certain to create an unsightly bulge and reverse taper, unless you plan on a tree in the sabamiki style and lots of carving. I would work on getting the roots/nebari straightened out & chop it back far enough to remove the scar (spring). Train up a new leader and allow it to grow until it's 2/3 the size of the main trunk and chop again. Maintaining the tree in the ground would fractionalize the amount of time it would take.

Al

I agree that waiting til spring is best, but the rationale of the tree's 'bleeding to death' is a long ago myth. Won't happen, though leaky sap can be unattractive and messy.

Where do you come up with these ideas? Show us something believable that states Acers will bleed to death from pruning while the sap is rising. From the practical side: I have dozens of maples that have been pruned harshly in the spring - roots AND shoots, and all are still with me.

Al

So should I make the large cuts now? If so, how should I go about the cut. Should maples have straight cuts or angled cuts?

Gardener Guy

Wait until spring. Your trees change from concentrating on using energy to add foliage and extend branches, to storing that energy/photosynthate as the summer solstice passes. Your tree has already begun preparing for dormancy by storing sugars, starches, oils .... that will keep its systems orderly through the winter and provide the energy for the spring push. Removing the top of the tree now will deprive the tree of it's energy producing machinery (leaves) and force it to use it's energy reserves to push new growth. This would leave the tree in a weak state going into dormancy - not a good idea.

I tend to make straight cuts, select a new leader from what sprouts, & wait for the tissue to die back a little on the weak side (opposite the leader), then carve out the dead tissue so the taper looks as natural as possible when it heals. Others angle cuts .... 6 of one, half a dozen of the other.

Al

Maples are amongst the few trees that can't be cut in spring as they will bleed to death if you do. Cut in winter while the tree is dormant and make sure you protect the cuttings with good wound paste.

@tapla: Do i need to add some scientific proof on this to? It seems you really like to kill trees.

Mmhmm - I think you do, and I think you're operating at beyond the limits of your knowledge. ;o) Make sure it's scientific proof, and not anecdotal. Remember to stay focused - we're talking about maple trees bleeding to death & not secondary/tertiary issues.

Al

I pruned all of my Trident Maples this Spring, and I know several others who've done the same.
I've pruned other kinds of Japanese Maple, as well.

None are dead. None even 'bled' profusely.

Josh