You'll probably find it needs more of a sheltered position...out of the winds and out of the strong mid day sun. It's also important that, whilst not drowning the plant, you never let it dry out.

It's a fairly common thing with japanese maples and often a position change helps. They should be fine in a pot...a weekly liquid feed with something like miracle grow should help from may to august.

The tree will lose it's leaves this autumn and the new growth should be perfect next spring. Unfortunatly, if any growth in spring gets damages by wind etc, you're usually stuck with it until the next spring.

Hope this helps

you must keep them moist to stop wind burn (which is what you are seeing.) the dissectum acers are very prone to it.
as andy says next year you will start afresh again, just keep it in a more sheltered spot out of very strong all day sun. thats why sometimes they are best in a pot. you can move them around!
these are my fav acers and i have 3 dissectums. all have a little windburn on them :-(
they are beautiful though.
my local pub have about 5 ot 6 and last night i went6 down there and was very distressed to find they hadnt watered them and they were all dead!!!!!! all were quite large and worth a fortune. clearly the new landlord isnt a gardener.
one of them though had the original acer (root stock not the grafted dissectum) still growing well as for some reason it had carried on growing?! not seen that before but goes to show how suseptable dissectums are to drying out.....

thanks! Very helpful!