Once the plant reached 6-inches tall I stacked another tire on top (sidewall removed) and filled in around the plant with more soil. I repeated the process after it grew another 6 inches. When the plant started to die back I lifted the tires and picked potatoes. Out of one tire I got 15lbs. Some varieties did better than others, but all told I got around 60lbs the first year. Now I do all of my potatoes the same way and get a couple hundred lbs a year.
This is a great way to grow potatoes as the tires tend to keep the soil at an even temperature, and the gaps between the tires provide a way for the soil to drain. I haven't had any problems with deer around the potatoes either. Not sure, but I think they just don't like the rubber. I haven't tried it with sweet potatoes yet, but might.
How do you store your potatoes? I have trouble keeping 5 pounds from going green and growing eyes.
I have a friend that has done the tire thing for years. Fortunately he has a small acreage and the unsightly tires can be put out of site and out of mind. His yields are simply amazing. With aesthetics being the case in a gated community I have a woodworker friend that makes stackable cedar boxes and does the same thing as if they were tires. Those beautifully hand crafted/dovetailed boxes are a thing to behold beauty wise. Even better looking with the plant foliage. His complaint .... “that ten pound bag of potatoes cost me 50 bucks to grow” But .. he had fun doing so.