The Tryptich published by the city of San Jacinto explains that those 4 zones characterize the southern end of the state: Chaparral, Mediterranean, Coastal and Desert. Each one of these zones requires unique criteria to water, based on the degree of tolerance shown by the plants, and wheather they require sun or shade, and how well they can stand extreme temperatures.
In his book Voyage Autour du Monde 1826-1829, the French travel writer Auguste Bernard Duhaut-Cilly wrote about José María Estudillo, in charge of the San Diego Presidio, and first in the line of the Estudillos of California. He had an experimental garden. In in a letter of 1827, to Francisco de Paula, analized by the Historian Catherine McShane, Estudillo told his friend De Paula, a resident of the Sandwich Islands (the old name of Hawaii) he was sending with Duhaut-Cilly “algedrae, mint, balmgentle, borage and rue I have cultivated in my home orchard”. And in the same source Mr. Estudillo is quoted as sending, from Santa Barbara, Rosemary, Olive and Peach Trees.