In the spot recently vacated by the sweet potatoes go our newly sprouted russet, reds, and yukon golds. We have planted potatoes from Nov. thru Feb. here and had good luck with all of them.
This year I had them hanging in our bedroom window in the 'solar dehydrator' for a month while they 'chitted' (fancy term for forcing them to sprout).
We plant them deep but don't cover with more than an inch or two of soil until they get to be about 6 inches tall. It's easier to 'hill them up' this way than to try and build up the soil above ground level. If you don't cover emerging potatoes they can be exposed to sunlight, turn green, and become toxic.
The final touch are the ever attractive 'cat guards'....doing double duty this year as protection for passers-by to keep them from falling into the holes. In other words....a lawsuit waiting to happen.
Or they could just be shade for the cat :)
More info on growing potatoes in California here.