It would help with more info ...you don't say if trees are in sun or shade or what varieties...if in sun then I know of nothing to help you ...maybe others do ... other than replant in shade. I am also NOT keen on daily watering ..a good soaking every 3-5 days sould be sufficient and over watering can cause alot of problems... If they are now in a shade or at least afternooon shade period then it's just TOO hot for em period or you need to try another variety or live with the anual summer ritual baring or leaves. David

I have 13 of them, most but not all are in full sun and temps are hitting 100 each day. I normally would never water daily, BTW its a light watering.. I have been living with the baring of leaves for a few years now just wanted to see if anybody had any tips or tricks to keeping them from frying. Even the ones at the store which are in shade are frying as well.. I know there is probably nothing I can do just wanted to throw this out there and see what I got back..

Tip to avoid fried leaves: Stop the daily light watering.

Instead, water less often, perhaps once a week. (In my region, once every 3 to 4 weeks works well, even when it's hot.) Ensure that the moist zone extends at least a foot deep.

And if the high temps are unusual, and the trees are small, rig temporary shade.

Really.. I was under the impression they were drying out? I have to water all my other plants and palms this way.. maybe the JM is different? Will try it and see if there is an improvement.. My viridis is coming back nicely and I have been giving it lots of water as its a newly transplanted one.. My baldsmith looks dead, the others just waiting for cooler weather

They may very well be drying out - and a daily "light" watering is doing nothing to alleviate that. As Jean indicates, a regular deep watering that soaks well down into the root zone will be of far more benefit. How often one needs to do that will depend on your weather and soil conditions and how long the tree has been in the ground, but certainly no more than weekly - if you are watering correctly.

And full sun in higher zones with high summer heat may be a bit severe a placement for these trees. J maples are generally considered to be understory trees in their native environment, receiving dappled shade from larger trees and this is a preferred light situation. Many cultivars can be grown in full sun, specially in climates where the sunlight is not as intense (such as mine) or the heat so severe, but may need additional attention to become properly acclimated.

FWIW, repeated defoliation from drought stress or other cultural factors is not doing these trees any good and could open the door to a range of other problems, some of which could be very damaging or even fatal to the trees. If I were you and value these trees, I'd go out of my way to ensure this problem is corrected ASAP.

This whole area will get alot more shade by next spring, hopefully that will help out. I dont see any magic treatments listed, as I didnt think there were any but had to post just to see.. thanks

Temporary shade would help.

And the "magic treatment" relies on getting the water to the root system. How long have the plants been in the ground?

Some are first year plantings others have been in the ground for 3+ plus years.. I actually have been watering alot as they are drying out and the sun and heat are killing them.. The ones watered more are the ones doing better.. but like I said next year will have alot more shade as my bamboo will be 20 ft tall and should give fairly good shade to most of my JM's