"At 12.36am on Saturday, July 20, 2019, the defendant was at Active+Physio on Maria Pl extension," police prosecutor Stephen Butler told the court.
"The defendant and an unidentified female exited their vehicle, walked to the edge of the building, picked up six pot plants and placed them in the boot of the vehicle."
Butler went on to explain that almost four hours later, McCallum and the female returned to steal two more plants.
Police executed a search warrant at McCallum's house following the incident and recovered all of the plants.
Lawyer Jamie Waugh said his client did not know what he was doing stealing plants.
"It's stupid behaviour and he accepts that," Waugh said.
Judge Dugald Matheson agreed with Waugh's comment.
"The theft, I think Mr Waugh said it all, it was just stupid," Judge Matheson said.
"The driving is the one that really concerned me. That speed in a 50 kilometre area was just dangerous to yourself, let alone others."
Judge Matheson sentenced McCallum to four-and-a-half months' community detention and disqualified him from driving for two-and-a-half years.