Vine maples are a common understory tree of Pacific Northwest forests, well adapted to the shade and moist soil of the region, though it will also take full sun and occasional drought in cool areas of the country. The long, thin multistemmed shape that gives it the name of "vine" maple is most often seen near stream banks. It is easily pruned into a variety of shapes, short, tall, single trunk and multistemmed.
Making the Cuts
Sketch a rough outline of the shape you want your maple to grow into on a piece of paper. Write a few descriptive words underneath, terms such as "tall, broad" or "narrow, high" or "multi-trunked, spreading."
Look at your vine maple and plan your cuts to shape the tree to the vision you sketched. Tall and narrow means taking off bottom and side branches. Tall and broad means taking off bottom branches and cutting the highest stem back to force out side branches.
Cut off all the superfluous branches, starting from the base and working upward. If you want a single trunk, choose one main shoot and cut away all others at the base. Always remove the major branches or shoots first, and work upward to the smaller ones.
Thin out the smallest branches if you want to force growth upward and outward. Maples have leaf and branch buds that are directly opposite each other, so when you cut above a node (the place where the buds sit) the buds on both sides are forced out, giving you two branches for one cut. To keep the tree open and airy, remove one of these buds, directing growth into the other.
Shorten the longest branches if you want to encourage the tree to be broad and bushy. When you cut back to a node, keep both buds, giving you twice as many branches. Or keep some as double buds and some as single.