Planting trees in Southern California

Climate note about Southern California

The Southern California coast extends from San Diego to San Luis Obispo and includes Santa Barbara, Ventura, western portions of Los Angeles County and Orange County and San Diego.

The Southern California coast is influenced by the Pacific Ocean and has a mild climate due to the marine air. Summers are moderate in temperature and coastal fog is common. Hot, dry winds, known as 'Santa Ana’s' can be damaging here and in the inland areas of Southern California. Inland Southern California includes Riverside, San Bernardino, Pasadena, Glendale, Burbank, the San Fernando Valley, Ojai Valley, and Santa Paula. The interior is more subject to hot, dry desert air than the coast and is considerably warmer.

Annual rainfall along the northern coast can be as high as 16 inches in Santa Barbara and as low as 9 inches in San Diego. Droughts are not uncommon, and all crops are irrigated. The main temperate fruit and nut crops grown commercially in this region are apple, macadamia, olive, peach, persimmon, and English walnut. Since winters along the Southern California coast and interior are usually mild and often frost-free, temperate tree fruit varieties with low winter chill requirements are usually chosen because the low latitudes in this region receives a more limited number of total hours (100~400) at 45ºF, which are necessary to mature fruit, than other regions in the state.