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Michigan Gardener | May 2018 | MichiganGardener.com
Pruning Japanese maples Learn the concepts behind the aesthetic pruning approach
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apanese maples enjoy widespread popularity and with good reason. They are a wonderful tree for a softening effect in the urban landscape. Naturally graceful when structured as an upright form (Acer palmatum) or as a weeper (Acer palmatum var. dissectum). With so many cultivars available, you can find them in almost any size and color. The Japanese maple is a true four seasons tree, and thus useful in almost any garden design. With such a great desire to have this tree, it is perplexing that more people are unaware of its proper care. It is important to aesthetically prune Japanese maples by hand using a pair of hand shears and a sharp hand saw. Weeping cultivars, otherwise referred to as laceleaf Japanese maples, especially benefit. The goal is to work with the tree’s natural character. When aesthetically pruning any tree in your landscape, it should be done for health and beauty as one. These are not separate. In terms of the tree’s health, you should consider how to prune in a beautiful way. Likewise, when working on a tree to enhance
When the buds on the maple begin to sprout growth, it has a compounding effect. This is part of the wonderful layering that Japanese maples create with their branches. The arrangement of buds becomes problematic on highly hybridized tree species such as the laceleaf Japanese maple cultivars. They are loaded with buds and the overall form of the branches growing out and down narrows the growing space, creating even more competition for light and room. This competition for space does not deter branches from growing. The active buds still send out Emily Foster Japanese maple branches that will crisscross over Fronckowiak health by pruning each other. Weaving back and forth Maple trees have a budding arrangement and even from one side of the tree all the way that is opposite. This means that the buds to the other. This not only creates a heavy and form along the stem in sets of two. One on gnarled look to the canopy, but it also blocks either side of the stem at the same point or sun to other areas of the tree, causing branch node. You’re getting double the buds versus death to the under, lower and back branches. an alternate budding arrangement, one bud The overabundance of branches, whether per node, interchanging sides of the stem. alive or dead, will collect dead leaves and can its beauty, you cannot do so without considering its health. When you remove a branch, for example, you take the branch all the way back to the collar, just in front of the textured ridges where it connects to the next stem or section. You would not leave a stub two inches in front of the collar. Doing so would create a ridged nub that draws the eye (not beautiful). As the nub begins to die back to the collar, it leaves an opportunity for insects and disease to enter the tree (not healthy). Always keep this concept in mind when pruning.
D R AW I N G S BY E M I LY F R O N C KO W I A K
hold moisture. This can be harmful to the bark of the tree, especially if it is happening at the top, over the central trunk. This is a common area where unnecessary branches are usually left and decaying leaves may become lodged. When Japanese maple bark stays wet for a long period of time it will begin to break down, inviting insects and disease, even if only in small areas. Given desirable circumstances to thrive, these unwanted guests will eventually kill sections, if not the whole tree. The solution is to create air movement by thinning out these unnecessary and dead branches. The right pruning will ensure the desirable branches get the light and air circulation they need (health), while keeping that graceful structure we love (beauty). Dead branches also accumulate after the winter from stress. Sometimes it is minor. Other times it is more extreme. This is often the result of the tree not being able to support
Three types of pruning cuts
Thinning cut removes entire branch
THINNING CUT Thinning cuts are used to open up the tree’s canopy. Eliminate redundant branches with thinning cuts. Make the cut at its point of origin, removing the entire branch.
This side branch will be the new leader
Re-leader cut removes the tree’s leader
Arrows indicate heading cuts
HEADING CUT Heading cuts are done by cutting back to a bud, leaf or node on that same branch. Use this cut to shape the plant’s outermost form and stimulate growth on the inner buds.
RE-LEADER CUT A re-leader cut removes the top lead branch. Use this cut to establish a new side branch as the leader. This reduces the tree’s height and slows its growth as well.