Name: greene Savannah, GA (Sunset 28) (Zone 8b) I have no use for internet bullies!
This is only a guess on my part - I have recently learned about the husk charcoal and that sometimes it retains too much moisture. Perhaps the two that did well liked more moisture and the two that failed would have preferred to be more dry?
I am also questioning putting manure in the mix too early on.
Sunset Zone 28, AHS Heat Zone 9, USDA zone 8b~"Leaf of Faith"