Many stonefruits and pomefruits, such as apples, apricots, cherries, nectarines, peaches, pears, plums and their relatives, require a level of winter "chill hours" to set a crop the following summer. Chilling requirements can vary widely from one variety to another and fruit selections should be made carefully. A fruit variety’s chilling requirement is a key determinant of where it will consistently produce satisfactory crops of fruit.

Several online maps and resources are available, but essentially all of urban Orange County is "low-chill". The closer to the coast the lower the chill hours, and some of the foothill and canyons offer a bit more chill. The milder your winters, the lower your "chill hours".

A very though explantion about fruit tree chilling requirements can be found

Height and width of fruit trees is often very miunderstood. The sizes listed here are of reasonably mature trees, perhaps 15-20 years old and with no size-limiting pruning.

Most deciduous fruit trees, such as apples, apricots, cherries, nectarines, peaches, pears, plums and their relatives, can be quite successfully maintaned at a much smaller size than shown, even up to 50% of the size indicated. Manageing the size of a fruit tree is best accomplished by "summer pruning". Winter pruning is important to develope a strong plant structure and for improved fruit production. However, tree size in managaged with summer pruning.

For a thorough discussion of both summer and winter pruning see

A series of outstanding videos on fruit tree pruning can be seen

Home fruit tree choices, especially when several fruits are involved, should always plan for successive ripening periods. Careful planning can insure ripe, fresh fruit for months, rather than being overwhelmed for a few weeks.

These ripening dates provided here are reasonably accurate, but may vary slightly depending upon location and variations in climate.