As a state California has one of the best climates, and some of the best soil in the world as well. In some parts of California you can literally grow most anything. Disneyland has some plants that were thought to only be able to be grown in small areas where they originated but Disney has made them grow in Anaheim. Of course Disney has a large team of horticulturalist so that does help. Even if you do not have a large team of horticulturist if you live in California you should be able to grow lots of different plants in your garden.
Gardening in California is easiest in Southern California, unless you are in a desert region. Even if you are living near a desert remember L.A. itself and much of Southern California would be desert if it were not for mans intervention. That means as long as you keep the plants in your garden well watered and if necessary in the shade. You can even do some gardening in the California desert. If you are in Southern California in an area that is not a desert then you can probably do any kind of gardening you want.
In Central California you will also have great soil and climate to start gardening. The only drawback that the Central Valley has is that it will get colder in the winter. The cold does not really become a problem until you get up to Northern California. While you can grow lots of plants in Northern California the winters and even early spring may be to harsh for some plants and the growing season is more limited then your gardening neighbors to the south.
Some plants that are great for growing in your garden are trees. A strong healthy older tree will not need watering outside of what it gets from mother nature, though getting some water from when watering, a drip system, or occasional watering will not hurt either and would be especially good for fruit bearing trees. Some good trees to grow in California are any kind of Palm, I prefer the California grand palm. Be warned palms can be messy. If you grow date palms you can also get the dates to eat but you have to like dates. Other great trees to grow in California are any kinds of citrus, they grow everywhere including Orange county, and even in Sacramento at the Capital. If you can get a good nut tree they offer an abundance of nuts, but need to be away from anything that could get hurt by falling nuts. Another popular fruit that does well are apples with many locations across the state having popular apple farms. Cherry, plums,peaches, and apricots are all good choices.
If you want to grow smaller plants in your garden the some good choices are berries. Some berries like blueberry, and raspberry can be hard to grow. Many berries like strawberries are pretty easy. Blackberries are easy to grow and grow wild in the state all over so growing in a garden is easy. Other common plants that grow wild in the state are a good choice because they use little water. Sunflowers, mustard, and golden yellow poppies are state flower are all good choices which will be easy to grow. Some easy to grow garden plants include tomatoes, and peas.
Gardening in California is easier then gardening anywhere else. With lots of good soil and climate you can enjoy gardening anywhere in California.