Here is an interesting way to grow potatoes in a small area like a small back yard, balcony or porch. With just a few pounds of starting potatoes you can buy in the local grocery store, you can have up to 100 lbs of potatoes at the end of the summer.
Potatoes grow from the center of the stem out. By placing a wooden box around the plant and add soil, compost or straw to encourage the plant to grow more potatoes up higher heights. As the plant reaches the top of the current box, let it grow about 4 or 5 inches higher than the box. Add more soil, compost and/or straw. Keep adding boxes and more soil until the end of the summer. Keep adding more boxes as the plant passes the current one. At the end of the summer take apart the boxes and potatoes will be throughout the boxes.
How to make the boxes:
Boxes shown below are made of old fence boards. They are cut to 18 inch lengths and screwed together on end with short decking screws to form a frame. Long screws split the dry wood. There is no top or bottom to the frames. Some people will put 2×2 boards along the corners of the boxes, but it is not necessary.