all i know about curing non mature plants is one of my corjo's blew down a month ago, breaking all roots so i hung it in my curing room. its still only half brown. the whole top half is still very green and flexible like its a fresh plant. also you have a large variation of size if there were all started the same time. i was thinking i would fertilize the small ones but i dont know at this time of year how the trade off would work between gaining plant mass vs ease of curing. and you said this is new dirt to you. did you till this ground up or just cover and plant. if not maybe your just unlucky and theres a big rock under each of the small plants. in any case theres something funky with the plot of soil if theres that much variance. lots of Hindsight Harold advice i could give for making plants happy next year, but im not sure what the proper advice is for now