The soil is just re-used soil from my indoor crops over the last year. Light-mix, All-mix and Plant-Magic (a UK company.)
I threw in a tiny handful of Grow-more and a small amount of bone-meal. That's it.
The trick is to dig MASSIVE holes for them. These girls got about 130litre holes.
I fertilised with Root-Juice for the first 2 or 3 times.
For the initial month or so of vegging I used Bio-Grow and AlgaMic.
From about the second week of July onwards it's just Fish-Mix.
I will stick to Fish-Mix until I decide I don't want any more Nitrogen. Maybe a month into flowering.
At that point I will change to Bio-Bloom and use it with Alga-Mic and Top-Max.
I don't use Bio-Heaven or Enzymes outdoors as they are far far far far far far far too expensive and not really needed at all.
To be honest, I don't think the nutes are important. You could get the same results with Baby-Bio. I know.
The most important thing is to dig a BIG BIG hole. Then double it!
The soil is not important. Any pre-mixed soil (intended for cannabis) is good. Just re-use your indoor soil (pull out as many roots as you can first.)
Also - In the ground, I don't alternate between pure water and feeds. I just feed a low concentrate at every water (maybe once or twice a week.)
I have tried the alternating thing but it seems the RO water just washes the goodness out of the soil. In pots, obviously, this can't happen as there is nowhere for anything to go (- so long as you don't have water gushing out of the bottom of the pot...)
One more thing - shelter, in the UK, from winds is paramount for a decent crop. NOTHING else matters as much. Forget placing your plants in the sunniest position if it isn't sheltered there...