The pictures look the same to me and when I research them, I don't find anything! How do I know what I'm getting and how do I choose? ==>> a few things come to mind... are you using the latin to search .... if not ... then you are getting general pictures.. under a common name .. they are all flowering cherries .... so you are hit or miss online ... if you are using the latin.. online search engines.. are still gathering info.. of cherries .. and you may or may not find what you want/need .. you are finding lots of pix on kwazan.. because it is so well know.. and becasue.. in the latin name it has quotes around it .... especially if you searched: Prunus serrulata 'Kwanzan' .. i not on your other types.. you have no cultivar name .... and therein lies your searching problem .... all that said.. if bloom is imperative.. then you buy a tree IN BLOOM.. and get what you want.. even worse than search terms.. is the industries attempt to PROPERLY LABEL things .. good luck with that .. especially bigboxstore ... e..g. if you are shopping for a brilliant fall color tree ... when would you think would be the best time to choose what you want ... make sense?? ken Here is a link that might be useful: link

If there has been a transition to different leaves with a different habit, with no flowers being seen you may have had sweet cherry rootstock sprouts grow up to overwhelm and replace a cultivar that was grafted on top. I often see this happening with Japanese flowering cherry trees here, even though the appearance of the scion and rootstock may be markedly different from one another at flowering time. If that is the case with your tree the portion that died may have been the last bits of the scion finally being killed off by the competition from the rootstock sprouts.

You might like to try Prunus mume, look how many kinds they have at the Raulston Arboretum. Here is a link that might be useful: Raulston Arboretum Search Result

It's probably the heat. Cherries don't do well in the heat. It should start to get better by the end of September if you keep the tree consistently watered. If you really wanted to go out of your way to tend to the tree, you could mist the leaves during the middle of the day (sometime between 12:00 to 4:00 ). I've even heard some people have very lightly sprayed their trees with mineral oil, or lightly rubbed some petroleum jelly onto the leaves, to help keep them from drying out. It's the height of summer right now, and a little browning is to be expected. San Jose has clearer skies than San Francisco, so less protection from the sun. In short, what you are seeing is perfectly normal for the climate you are in. There's a reason most commercial cherry orchards are based in Michigan and Eastern Washington. Also, in San Jose (all the paved surfaces in the surrounding area has an effect on temperature) it's quite likely your kwanzan trees are not getting quite the degree of winter chill that they would prefer. This results in slightly reduced vigor, and that is also associated with browning of the leaf tips. Your tree should fair better in future years when the roots have become more established (and they can provide a more adequate water supply to the leaves).