Two cannabis factories were discovered after police officers smelled the drug in a Mercedes they pulled over at Hunton Bridge.
Pedro Faustino, a 37-year-old Portugeuse man, was stopped in Watford Road on July 20 this year, St Albans Crown Court heard on Friday.
When the car was searched a knife and £3,000 in cash was found. Faustino gave the officers two addresses where cannabis was growing.
They found 80 plants in Little Hill, Rickmansworth, and 244 more at Acre Wood in Dimmocks Lane, Sarratt. There was also another outbuilding in the village that had been used to dry an earlier crop.
The 324 plants could have yielded 13 kilos of the drug with a potential street value of £130,000, said prosecutor David Chrimes.
Faustino of Popes Road, Abbots Langley, pleaded guilty to possessing 5.67 kilos of cannabis with intent to supply, production of cannabis and having a blade on July 20. As each charge was put to him he said: “I am sorry, guilty.” He had no previous convictions.
Kate Barbour, defending, said Faustino, who had come to the UK in 1997, was not aware of the seriousness of the offences. He had been in a significant amount of debt after his chauffeur business had failed. He had separated from his wife, but they were now reconciled, she said.
Judge Stephen Gullick jailed him for 18 months. A confiscation hearing will be heard at a later date.