Judge Duncan Harvey said it was not clear whether Bartlett, a cannabis user, was alone in the drug cultivation on 13 plots.
He said each plot was surrounded by mesh wire, fishing net, and small fence-like structure where gin traps were laid to attract possums.
It was clearly a sophisticated outdoor cultivation designed to achieve a maximum haul, Judge Harvey said.
He found it interesting police found no evidence of cannabis use in Bartlett's house, given he smoked cannabis.
Bartlett has been assessed as at a modest risk of reoffending and at a moderate risk of harm to others.
Judge Harvey said it was clear Bartlett had experienced a very difficult childhood and lived an isolated life.
He is in a long-term relationship and has a daughter who was present in court to support him.
"You say you have a drug problem and you wish to do something about it. You say you feel better having not smoke cannabis for some time," Judge Harvey said.
He could not understand why Bartlett took the case to trial because he did not have a defence.
Bartlett was a good member of the community and father, Judge Harvey said, and it was a shame it has come to this.
He sentenced him to four and a half years in jail.