Yes I think that depends on the soil, but we are experimenting with deep holes vs trenches and so far haven’t seen much of a difference. Our soil is pretty loamy, but we do have quite a few rocks which makes hand digging tough. When we put up our garden last year, it included putting large timber around the perimeter for the fencing... the hubs got an auger to make that job do able and its just been an easy way to get some holes dug quickly haha. I do try to losen the sides to encourage roots to grow horizontally as well.

Thank you!