Full defoliation of a maple will prompt another flush of growth in the current season.
On a healthy, mostly developed tree, it’s a good way to improve ramification by adding a second course of twigs in one season.
On a tree that is more developed, the goal changes from increasing density to allowing more light and circulation into the interior of the tree. This is done by partially defoliating the tree, and can be viewed as an investment in the tree’s future, assuring something to prune back to during ongoing refinement.
This tree is “off display” right now. I am working on improving the nebari with some thread grafts, changing the front and planting angle a little, and preparing it for reducing a large branch in the upper left portion. It has spent most of this year with the back facing the sun, and the pot tilted up on a rock to encourage the thread grafts to grow to the sun! A long-winded way of saying that it looks a little rough right now, but should be a much better tree in 5 years.
Back to the topic at hand…as it looked before partial defoliation: