Yes, winter is a great time to grow in Southern Ca. pretty much all the cabbage family, all greens and such do very well in the winter. Herbs like cilantro do great. Potatoes, carrots, beets all grow well, so do peas.

Summer is more for tomatoes, eggplant, squashes of all kinds and such. It really is great here for having a garden - besides the fact that there is always garden work to do and not so much winter downtime like in the colder climates :)