How can I tell when an avocado is ready to be picked?
Avocados have a tough leathery skin. They are often delivered to the grocery store quite under mature to extend their shelf life and reduce bruising. As fruit ripens, the oily flesh inside softens so the entire fruit becomes softer, especially at the stem end, but the skin remains rather leathery. People use the fruit at different levels of ripeness depending on the use and personal preference.
You may wish to contact the local University of California Extension Office in Los Angeles County. They will have a master gardener program where you can receive more detailed local help. http://celosangeles.ucanr.edu/