When do people in Southern California replace their vegetable plants?

Question:I heard that in Southern California, the temperature doesn't go below 60, so people can garden all year long. In the north, our vegetable plants die in the fall from frost and we plant new ones in the spring. If you garden all year long, when do your plants die? How long, for instance, does a tomato plant stand there and make tomatos? It has to die at some point, right? When do you replace the vegetable plants?

Answers:
I live in southern california and i've had pepper plants keep up and producing for over a year. Now most of my bulbs - tulips ect do not survive unless I dig them up and store in the fridge. Whereas when i lived up north I could leave them in the ground. So it's just a trade off.

My herbs survive year round too and stay green and producing.

We'll see this year on crock neck squash.