Potatoes can be farmed using a farming plot. Each plot can only hold one potato plant, and will yield 1 potato once ripe. It takes 4 stages of growth for a potato plant to grow into it's fully mature stage.
Aside from eating, potatoes are also useful for refilling Jerrycans after they were converted into gasoline. 4 potatoes are needed to full refill a jerrycan. Can be eaten for 2 food bars.