I'm growing potatoes in a bin for the first time

[Backseat Driver]

8. My attempt to grow potatoes in a deep-boxed bin failed.

Unsure about the reasons as I watched those youtube videos and thought I had followed the tips to growing them re: planting, adding dirt as the green parts grew; adequate sunshine and drainage. Above ground, the plants looked great. The roots from which the potatoes were supposed to grow in abundance just made very few vegetables below the ground and what there were -- small, soft, and deformed; nowhere near a 50 lb haul of anything usable. I can only think the dirt used to fill the bin did not provide the necessary nutrients???

Here's hoping your attempt will be more successful!