Van Gaalen had told the court it was for personal use and to give away to about 20 close friends. She had two plants, one of which had grown exceptionally well. She said she smoked cannabis daily and had started when she was 14.
Judge McDonald said there was no evidence of commercial dealing, such as text messages on her phone, but Parliament had set the upper limit for personal use at 28g. Van Gaalen had 24 times that and knew it was against the law.
"It is not for this court to comment whether that is a just law or not," he said.
Defence lawyer Doug Blaikie said he had been flooded with unsolicited references testifying to her good character and work in the community. In total 32 references had been provided by a range of people, including a former mayor, a principal and a pastor.
Many vibrant citizens had deserted Kaikohe but she had chosen to stay. Town beautification projects had ground to a halt after she had resigned from her roles, Mr Blaikie said.
Kaikohe Business Association chair Steve Sangster also addressed the court, speaking of her achievements and the pride she had instilled in the town.
Judge McDonald gave her credit for her previous good record and "extremely worthwhile contribution", but said he had to be consistent with sentences imposed for other, similar offences.
"To say this sentencing has troubled me is an understatement," he said.
Crown prosecutor Catherine Gisler had called for three years, saying deterrence was important. Mr Blaikie had asked for a term of community detention.
Van Gaalen's husband originally faced the same charge. It was dropped when she said the cannabis was all hers. Her family is planning to lodge an appeal today.