In my neck of the woods in my part of the Sierra Nevada foothills most growers have opted for breathable fabric containers, such as Smart Pots, most biggies are running 300+ gallon, and the others are plastic ag bins (4'x4') with slits for air and drainage, and raised bed planters , and most truck dirt in, and either premixed for season or they add amendments before filling containers....now the grower I worked with and learned a little from this past season has used his holes for 4 years now, it took 1 season before that to just remove all the rock, till it all, and then add what he needed and then tilled it again, and still his 1st year he burnt a few , but did great nonetheless, and he had his most epic year last year, kudos to him, they were so beautiful!!!!