There is a lot of babble on the internet about growing potatoes with stalks supported by tires and using straw for covering. To my way of thinking this is only complicating matters. One hilling of plants after the main stalks emerge is probably more than sufficient. The view seems to be that potato tubulars are produced along the stalks, which is simply not the case.
New potatoes grow from shoots emanating from the very bottom of the stalks in a circle, almost from the seed potato itself. No new potatoes grow below the seed potato. The new potatoes must be protected from light, otherwise they turn green and are somewhat poisonous.
Hilling is done to protect the new potatoes from light, and the earth tends to support the weak stalks, since they tend to fall and spread out.
Study the attached pictures, which supports my view.