They charged father-of-six Gregory William King, 47, with drug trafficking after his DNA and fingerprints were found on latex gloves and a fertiliser bottle seized from a growhouse fitted out with lamps, fans and heaters in the garage of the Chisholm house.

King pleaded guilty in the ACT Supreme Court shortly before his trial was to begin and admitted to a pre-sentence report author this month he had intended to sell the cannabis and had also swapped the drug for cocaine.

That plan lost King his family home, and his liberty for nine months, when Justice David Mossop sent him to jail for "clearly a deliberate and organised activity" driven by his desire to make a profit and get more drugs.

His defence team argued the 8.67 kilograms of cannabis seized was towards the lower end for a trafficking offence and it was impossible to determine how much King intended to sell, while prosecutors said he was clearly a user and dealer.

Justice Mossop said King's history of similar drug offences earned him little leniency and showed sentences that stopped short of full-time custody had been "ineffective" in deterring him from trafficking cannabis.

He said King's family home had been confiscated under proceeds of crime legislation.

King, a former public servant, was a heavy drinker and began using cannabis when he was 15.

He had been using a "significant" amount of cannabis and sometimes hashish at the time of his arrest, when he admitted his cocaine use was "out of control".

In handing down his sentence on Wednesday, Justice Mossop acknowledged the impact of a jail term on King's family, given he was sole breadwinner, would be significant and their housing situation was "tenuous".

But he said no punishment other than time spent in full-time custody would be appropriate.

He sentenced King to 18 months imprisonment, to be suspended after nine months upon entering a good behaviour order for 30 months.