Caring for Your Ornamental Maples

Spring is here and trees everywhere are sprouting their leaves and blossoms, creating an eye-popping spectacle throughout the area. But while your eyes are drawn ever upward to the beautiful sprawling trees above you, your smaller specimens might have escaped your notice. So we’d like to turn your attention to one of our favorite ornamentals, the weeping Japanese maple:

When your maples leaf out in the springtime and turn into a bushy mass, it’s easy to be overwhelmed by the task of pruning. In this example the tree encroached on the driveway and sidewalk, and closely resembled a Muppet. You can no longer see the tree’s remarkable branching structure — which is really where all the fun is in having these trees on display.

Now many people’s natural instinct when dealing with with an overgrown laceleaf is to attack it with a hedge trimmer. The negative effects of this treatment are almost immediate: the chopped-off tips die off, leaving unsightly stubs, and the new tips grow back even bushier than ever. Now that the ends are overcrowded, the next generation of growth will reach out even farther to take in the available light. This begins a vicious cycle that makes the problem three times worse. It is usually possible to correct this with proper future prunings, but it’s much more difficult than pruning an un-hedge trimmed tree:

The second most common improper practice we find is when people simply cut the ends off of branches, leaving long, thick arms behind that terminate in stubs. Often these stubs simply die; other times they will generate bushy sprouts. Either way it produces an unsightly result:

The above is also a prime example of over-thinning the canopy. Removing too much of the canopy results in sprout growth, dieback, or even sunscald if the trunk isn’t properly shaded:

So what is the proper way to prune a laceleaf?

Make no mistake: pruning one of these maples, especially one that is particularly overgrown, is a daunting and tedious task that requires a lot of patience. The easiest way to start is to crawl under the tree, like a mechanic, and get a view of the canopy from below. Why? Because about 90% of the work is down there where you can’t see or reach from the top. Yes, this task will get you dirty and it can be hard to move around. But if you have a hard time getting under your tree, don’t worry — we’ll be happy to do it for you!

Once you’re under there, the first task is to remove any obvious deadwood you can see. Especially in a tree that has gone untouched for a long time, removing the deadwood alone will eliminate most of the work of cleaning the canopy, and will also make it easier to move around.

After the deadwood is gone, the rest requires an artistic eye and a good knowledge of basic pruning techniques. First, you want to be careful not to remove too much live growth. If the canopy is too thin, the tree will respond by shooting sprouts. Also, exposing the branches to too much sunlight can inflict sunscald damage. So alongside patience, moderation is key.

The good news is, sometimes the worst tangled and overgrown specimens are hiding the best branching structures underneath — cool twists and turns and branch fusions, and sometimes even distinct tier structures. By selectively removing the excess crowding and choosing the best structures to keep, you will eventually reveal the inner beauty of the tree.

Here we’ve cut the tree back away from the walkways without leaving stubs, leaving an orderly and natural edge. Though it’s hard to see in the picture, the canopy is thin enough to see the internal structure but not so thin as to stress the tree’s health. A good pruning takes patience, practice, and an eye for visualizing the outcome of your cuts.

These trees are especially popular around the Portland area, where our staff arborists have made these a particular specialty. If your weeping maple has gotten unruly and can use a makeover, give us a call and we’ll be happy to give you an estimate.

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