All I can tell you is how I grow mine !! I "dug out" a trench, about 16" deep, 3' wide, and as long as "needed(for the number you intend to plant), lined it with rubber roofing membrane (a few layers of plastic sheeting would work), but leaving the top 4", or so, of the trench "uncovered".....then filled it to the top with "peat" soil , mixed with "composted cow manure", and some "river muck" I got from our local riverbank......the "peat" is naturally acidic (slightly), and really holds water (as does the "cow poop", I added some "garden sulfer" to get the ph where I wanted it, planted the rhizomes, and mulched the area with pine straw (also helps with ph)…...twice a year.....spring and late summer....I fertilize and add more sulfer. Our dirt is very sandy, and while our springs are "wet", our summers and early falls are dry..."rain wise". The humidity is brutal, though, once the corn gets going !!
Anyway, that has worked well for me for the JI's, and LA's