How Deep??
 

How deep do I plant Yukon gold and small red potatoes?

Woose, plant 3 to inches deep and after the plants have emerged and grown 3 to 4 inches tall, pull up soil to the plant, covering the stems so only about 1 inch of the plant is sticking out of the soil. Repeat this process every time the plants are 3 to 4 in inches tall until you have a mound of soil about 10 to 12 inches tall in the row where you plant potatoes. This process is known as heeling the potato plants and the potatoes will grow in the soil you have heeled.

Same here. 3-4 inches. I've trenched and used the mound method. Then a couple years to save space i built 3 3x3ft simple raised beds, 2x12 board, filled one as the 'planter' and as the plants grew i added another 3x3 on top and filled around plants, re-peat. Just went up with it. Really good production in a small space. You can plant a bit thick in a raised tower bed.

I got lazy and don't trench. I use a bulb planter and plant about the same depth.