Were they putting the grow bags in the ground and getting similar results?Telperion Farms use grow bags, and Ryan Neal loves to buy their material. The topic is covered in an episode of the podcast Asymmetry. I recommend giving it a listen. They are seeing idententical growth rates as growing without the bags, but the root system is more compact and easier to transition to a pot. Their speculation is that you get the microbiome and even moisture benefits despite the restricted volume of roots.
What size do you use? @moke too!I like it,just have not did it yet.
Just make sure you use heavier bags by Rootpoch Brand .They are the only brand I know that uses entrapment pruning and can last a few years or so in ground.
Other brands air prune and roots would row into ground and defeat purpose.
I use them all the time above ground.
Here's the link to the item I am using, I bought several different sizes.