I have a 4x6 garden box elevated 3' the ground. I am going to try sweet potatoes only as my first try at gardening. I have the slips. I need the right soil and my research does not give me a definitive answer-calls for too much speculation on my part. I have: 2/3 part mix of top soil and sand mix, and 1/3 Black Kow compost. I am tossed about using the Black Kow as opposed to a vegetable compost. The cost for me is critical and I do not want to mix the mix and plant the plants until I know if I have the right direction.
Vegetable Gardening Soil
Certified GKH Gardening Expert
The Black Kow compost should be fine. If you already have some veggie compost available and it is cheaper for you, then by all means use it instead. It will be fine either way. Simply mix everything together. For additional information on growing sweet potatoes, this article will help: https://www.gardeningknowhow.com/edible/vegetables/sweet-potato/grow-sweet-potatoes.htm