Many of you in coastal Southern California may have tried growing apple, pear, or stone fruit trees and found they did not grow well.
I have found a technique that may be very helpful. If you are having trouble growing apple or stone fruit in Southern California, putting a tarp over it to give it partial shade can really help. The best time to cover it is from late December to January, and also from June to September.

In the Winter the shade helps allow the tree to fully go into dormancy, because even just a few Winter warm days can really detract from the amount of effective chill hours the plant accumulates. It is not only temperature, I believe the light level itself plays a role, the tree can still sense light intensity even if it has no leaves. Come Spring, the tree will began leafing out much more vigorously and sooner if it got an adequate chill accumulation.

Summers in Southern California are notoriously hot and dry. In many other parts of the country it is Winter that is the most difficult time for plants to grow, but in Southern California it is the Summer that is the most difficult season for plants to grow. With the clearer skies, higher temperatures, dry air, and lack of rainfall, the leaves of many plant varieties can get scorched. Consistent watering during this time is important, of course, but the plant is still going to have a challenging time coping in these conditions.
This happens to be the reason that deciduous trees typically do not grow as well on the West Coast, by the way. Because Winter is the time of year that all the water falls, so the plants best adapted to the region will still have their leaves in the Winter.

Having a little bit of shade can really help deciduous trees grow in this climate. Many of these trees supposedly "need full sun", but what you have to realize is that what applies in other climates is not necessarily going to apply in Southern California or the Southwest. Southern California tends to have a lot of sun. At least in Florida there is plenty of the humidity so the plant's leaves are less likely to become dried out. I have observed that it is better for the plant to have a little less sunlight than optimal than it is for the plant's leaves to get more sunlight exposure in a hot dry climate, this essentially has the effect of baking the leaves and they turn brown.
You can also try to plant the tree in an area where it will mostly only receive morning sun. I have been able to grow Lilac and even a Lingonberry bush this way, south of Los Angeles (and yes, they flower and fruit!). For deciduous fruit trees that need more chill, you can plant on a north-facing wall. Come the Winter season, the trees will be very shaded.