Along with pine trees, this is the time of year to perform a reduction prune on your Japanese maples. A close friend of Momiji-en has for years referred to weeping laceleaf Japanese maples as “Mr. Snuffalufagus,” the large furry creature from Sesame Street, for their shapeless overgrown appearance after leafing out in the spring.
This mounding pile of red leaves needs to be thinned, layered, and opened up, to produce the classic lace-like layer of leaves and drooping branches celebrated in Japanese landscapes. This not only increases air flow and sunshine to the interior but also creates the elegance these maples are known for by revealing their inner “bone structure.”
Over the years I have found it is necessary to do the majority of this kind of pruning by working from the inside of the tree and from the top down. Watch how the layers “lift” as you remove the weight of some leaves and branches. From here you can most easily identify the downward growing shoots and the overlapping layers of branches. The removal of these is aided by the fact that working this way you can see the remaining branches and leaves nicely back lighted by the sky. Simply work where you see it is the most dense until you have an even overall texture.
Avoid the danger of removing leaves and branches from the outside layer where you would be uncovering branches and leaves that have developed under the cover of others. This makes them now vulnerable to sunburn once they’re revealed as the new top layer.
Like other tree pruning techniques, the more often you treat the trees in this manner the easier it is to do each spring. Be prepared that it may take years to develop an interior that will even allow you to get inside, let alone stand up under the tree. Prepare the tree by opening it up from the trunk with larger structural cuts in the winter when it is bare, dormant, and the branching armature is easily more visible.
The aesthetic rewards of this somewhat tedious work are worth the time and effort.