seriously though, the potting soil looks a little loose, might not be retaining moisture the best, it's very common for the roots of young cherry trees to have difficulty providing adequate water uptake in warm climate regions where the leaves are exposed to a lot of sun.

That particular low-density potting soil may not have been the best choice. If possible, see if you can mix in some compost in there, but be careful not to disturb the rootsystem close to the cherry.

trying to drown the roots isn't a good idea either, but make sure the soil is kept moist. When the tree gets another foot and a half taller, you may want to shift over to a deep watering once a week.

nurturing a newly planted cherry tree is an art, and a lot of this is intuition that will come from years of experience. stone fruit can be notoriously finicky

Your cherry tree is getting dried out so I'm going to take a guess that you live on the West Coast. (or central Texas?)

Thanks very much.. I was also suspecting that it may be a watering issue.. it is on ground, clay soil, with compost / mulch on top... I am in San Jose and it has been very hot..

will connect to my drip.. was not doing it and watering deep 2-3 times a week..

did you put heavy fertilizer? it almost looks like a reaction to that. Also, if you have heavy clay soil, you have to be careful not to let the roots get water-logged. Cherries like deep watering about once/week, but in clay soil, you may need to have it raised above the surrounding ground so it drains properly.

May be.. it was stunted after initial growth.. thought fertilizer is needed and spread lots of compost / fruit tree fertilizer on top.. it is not water logged..

looks like either nutrients or over fertilization or watering issue & not a disease? SHould I check pH? Soil may be a bit alkaline..

It's not about giving your young tree a big amount of water, it's about keeping those roots moist. And in certain types of soils, or certain types of climate conditions, it may take more water, or more frequent watering, to make sure the roots remain moist. This is true for a young fruit tree. Later on after the tree has become more mature and the root system has established itself, things become different.

It's also true that if the roots of a young fruit tree sit in a pool of water too long, it is not good for the plant and the tree can die. So try to make sure the soil is always kept moist but at the same time well-drained.

Planting a young tree in loamy soil (or with compost mixed in) helps because this type of soil retains water better and does not dry out so easily. A lot of potting soils that are being sold now are basically mostly tiny wood chips by volume (this is to reduce weight) so basically do not hold moisture well. This appears to be the type of soil you used in the picture. Too much woodchips and perlite make the soil too porous, then it does not hold water. (on the other hand, some soils are so rich in clay and limestone that water can't seep into the soil, and this type of soil can be very dry as well)