Do you see any bugs or beetles? Can you post pictures?

Japanese maples are disease susceptible and sensitive to impeded drainage. They are also woodland trees that may be damaged by hot sun in summer. If you look around a bit you will see there have been multiple others with Japanese maples that are dying back etc. Some stock may be coming from nurseries already infested, due to apparently careless propagation and production practices.

I have seen something similar in fruit trees - my apricot, and also in my sisetr-in-law's weeping cherry. Her cherry died, my the apricot lost a few branches and is doing OK. Here we have had silver birch trees and london plane trees effected by some kind of virus which kills off smaller branches. The first thing you notice are leaves turning brown, then the branch dies back to the stem of the tree. The disease in the apricot looks similar to you dieback diseas, but as the bark is brown and rough, the blackness can't be seen as easily. My theory is that it is stress from hotter/drier weather.I haven't touched my trees - not cut back anything or sprayed, preferring the 'wait and see' approach. So far, they are holding up... Robyn

There is not a single topic where qualified horticultural professionals do not have dissenting opinions. Indeed, over time, yesterday's crackpot theory becomes today's widely accepted practice. Andvthe reverse is equally true. I can provide examples of each. I have no problems with disagreement...it means we have views that are different, nothing more. I can tell you this much...technically, no diagnosis should be given without a lab report. In practical terms, symptoms are given, probable diagnosis are given, no lab ever consulted. Same with nutrient issues. Very few are going to go through the trouble of collecting samples, sending them in, and waiting...and nearly every soil test i've ever seen has at least a token amount of fertilizer recommended. And who exactly is going going to go for a tissue analysis? Except in extraordinary circumstances? So making this claim is misleading, it's an attempt to shut down dissent, not create a conversation. Let's not even start going down the rabbit hole of analyzing and interpreting soil test results...basically, that's one subject where there is no agreement. I'll admit most people fertilize where they have no business doing so. I won't comment on some of the products out there or the claims made by various parties. In particular instance...we have a plant recently acquired, still in a pot. Trying to exclude container practices while claiming the umbrella of established landscape plantings is misleading. For the record, i'm not suggesting we fertilize this puppy till there is no fertilizer left on the county. I'm suggesting a half rate dose of a liquid soluble, aka, a shot in the arm. It can do little harm...and can have the benefit of pushing new growth. Explaing how photosynthesis occurs...great...now, how do plants take up nutrients? There needs to be room for dissenting views, in many forums of life. I'm not promulgating crazy high doses, or mix your own concoctions because i took a high school chemistry class...this is not a radical proposal i'm making. And frankly, it's one respected horticultural professionals across the country give routinely. Feel free to disagree...you can be a qualified and respected professional and disagree. Especially in horticulture.