The box I cobbled together from old pallets, dirt is a mix of potting soil and local dirt spiced with chicken poo.
For the more observant viewers, you may notice that the closest 'V' is slimmer than the upper square -- the pallets were a little short. I plan to plant smaller vegetables in those areas.
Op was referring to the square foot gardening method, you can read more about it and the book here: https://squarefootgardening.org/ There are tons of YouTube videos and blogs writing about it too, if you prefer that over a book
Thank you!