Bare branches on little red Japanese Maple & junior ash tree
We have a little Japanese red maple that was doing great for a few years but this year has many branches that seem to be without foliage, and we are not sure why. Photos enclosed. We have experienced the same with a junior ash tree. The photos were taken this past weekend, so this is not from Spring time when you’d expect some branches to be bare as the leaves develop and come out. Could you take a look at the photos and see if you have any thoughts or suggestions? If you think they have something could infect other trees in the yard, let us know. I am debating about just removing the ash tree because of the concern of the emerald ash borer. The branches that are bare don’t necessarily seem to be dead, which is very strange, and leads me to think this is not from winter snow & ice damage.
While we are unable to diagnose the exact causes of your trees' problems, there are some general observations to be made. The young ash tree could be suffering from a root problem or it could be a boring insect (ash trees are susceptible to several species). You might look for any signs of insect damage. Typically, you would find entrance or exit holes in the trunk. Unfortunately, from its appearance, the ash tree is a candidate for removal.
The maple tree may also be suffering from a root problem, since the upper canopy appears rather sparse and there are no clear indications of disease or insect activity.
The bark of many thin-barked trees, including maples, will sometimes split when weather conditions promote an unusual spurt of growth. Other environmental causes can result in similar splits. This, of course, can allow insects and pathogens to enter the vascular system of the tree. Exposure of the vascular system can also disrupt the normal flow of water and nutrients through the cambium layer which is located immediately under the bark.
The good news is: the maple may recover, even though there is no treatment that can be administered. Also, there is nothing observed that would spread to your other trees and landscape plants.
The best thing a homeowner can do is to get to know your plants intimately and monitor their health and well being regularly. Also, provide supplemental irrigation to your most prized plants during hot, dry periods.