You're not keeping up with the watering sufficiently well - cherries are shallow rooting and need lots of water, and any new tree (if you only planted last year, this will count as a new tree for its first two years) needs a minimum of 2 gallons a week in a normal summer, and probably 3 times as much this year if you live in the south. Leave the hose running at the base for a few hours or overnight, moving it to different sides.

just read this

as my cherry was looking little bit wilty in hot weather even tho i thought i was watering sufficiently ... thanks hopefully the terrential rain is over now and we can resume the heat wave ... and i can give it the water it needs although without the hose of course !

thanks alison . wow its amazing what u guys know !

Why without the hose Wheely...? Unless you live in Cumbria, I'm not aware of a hosepipe ban anywhere else, is there one?