have some trees a little further inland, maybe 10 or 20 miles south of Irvine, and they are very reluctant to fruit.
The Royal Lee have not fruited yet, even after 5 years. One of the Royal Minnie is grafted onto the top of a Bing cherry and the tree has reached a medium big size. This year I got one single cherry fruit on it, which looks like it will ripen. This is the first fruit so far that hasn't dropped. I also got a small bunch of maybe 7 cherries on another Royal Minnie tree in a container that is in mostly shade. It's base rootstock was overgrown and the suckers needed to be cut off, and the top grafted part of the cherry did not look so good; it might have only sent out fruit because it was under severe stress and dying. The cherry fruits were small and looked like not a lot of vigor went into creating them, like they began overripening before the cherries had fully matured, although the flavor was just okay.
Maybe when the trees get bigger and a colder winter than usual comes along there will be more luck.
The area is in solid zone 10 (on the border between 10a/10b).
The Royal Lee trees seems to be growing just between okay and good.