About 4 years ago, we found what we believe to be the best way to grow sweet potatoes. In a box filled with sawdust and sand using the Mittleider gardening method. In addition to this being the best way to grow a sweet potato, it is the simplest way to harvest without heavy machinery. When it is time to harvest, we are able to pull them all out by hand, no tools of any kind necessary!
Our grow box is 4 feet wide and 15 feet long. It was constructed out of treated 2 x 8 lumber. After leveling the box, we filled it with a mix of sawdust and sand. (The sawdust can be from any tree EXCEPT walnut.) It is mixed in a ratio of 3 parts sawdust to 1 part sand. After mixing thoroughly the box is filled level with the top of the box.
As a slight aside, there are no nutrients in the sawdust and sand for your plants. If you do grow a garden this way you will need to provide all the nutrients your plants will need. They were fed weekly and watered daily. It is simple and inexpensive, and is part of the Mittleider gardening methods. We have an extensive MGM playlist on YouTube. You can also find more information on Facebook in the Mittleider Gardening Method group.
After our first frost of the year, we went ahead and harvested our sweet potatoes. You can watch in the video and see how easy it is to harvest sweet potatoes grown in sawdust and sand. You root your hand around in the sawdust and sand and pull out the sweet potato. In two rows of sweet potatoes in a 15 foot long box we harvested 83 pounds of Georgia Jet sweet potatoes.
Watch the video and decide for yourself if the best way to grow a sweet potato is in sawdust and sand.
Link to video on correct sawdust to use in your Mittleider garden grow boxes -