The mulch/soil seems to be pile up quite high around the trunk. That needs to be pulled back. It could be contributing to the dead branches.

@floraluk2 I'll pull back the mulch. The company that added the mulch

this year also piled up the mulch on the bulbs of my irises last year. I had to pull it away. I'll let them know to go light around the trunk next time. Thank you!

Most bulbs will happily grow up through mulch but bearded iris, which have rhizomes rather than bulbs, need them semi exposed to the sun. That's if yours are bearded iris.

Yes, bearded irises

I'll second gardengal, minimally prune your Japanese Maples. And I beg you, please do not trim the end of every branch up 2 feet off the ground so your JM looks like an umbrella--not what nature intended.

I just bought a "Red Dragon" to replace a 7-year-old "Inaba Shidare" that died a few years ago. RD wasn't the exact JM that I was looking for, but in a 10 gallon pot with a trunk size over an inch for $200, it became my new favorite. The nursery didn't appear to trim this maybe 3-5 year old Red Dragon at all, so it needs a little work. I will try to post pictures when I prune it. What I do is get on your knees by the trunk and look up at the underside of the canopy. You will likely see brown to gray dead branches here and there--best practice is to use pruners to remove but I honestly snap the small ones right off. The only other goal I have is to make sure the horizontal branches are not hurting each other anywhere. So I look for larger branches in the canopy (smaller ones I wait to see if they correct themselves) that are touching each other, or worse one is rubbing the bark off the other or they're both rubbing already. When this happens, one of the two branches has to go, I pick the one that will have the least visual impact on the tree but you can use whatever criteria meet your goals for the JM's appearance.

For fun here are my roughly 10-year-old "Crimson Queen" and "Viridis." That is a 6 foot fence behind them, and as you probably know the weeping JMs tend to grow wider than they do tall. I prefer the appearance of a taller, more graceful tree (that will fill in to the ground eventually as if you left it alone anyway), so I've "trained" several of my JMs for more height. If you're interested, I can start a separate post showing how I do it or there are already several on here if you do a search. You basically get a bamboo pole that is a foot or so taller than your JM, stake it into the ground near the trunk, and take one of the topmost branches of the JM that is starting to" "weep" nicely and tie it gently to the stake so it's basically facing the sky. You can use a section of cut hose or other protection for where the string is holding the branch, but honestly again, those top longer branches are so flexible that I just use bare twine and have never had any bark rubbing issues.

Good luck, JMs are easy and fun to prune (almost like bonsai) and you really can't beat the results, I think they're so beautiful.

Chris

Gardengal is correct. For big shade trees, branches heading back toward the center and crossing are almost always best corrected. This is not at all true for the smaller, spreading JM's. Curving, hooking, twisting branches, and even fused branches, add tremendously to the overall aesthetic as these trees age. Go to a botanical garden with very old specimens of spreading JM's and you will see, and better understand how beautiful the branching will become with age, and that if these erratic branches were "corrected" when the tree was young, it would not be nearly as spectacular in old age.