Shannon Morgan, 21, was sentenced at the County Court of Victoria via video link on Tuesday for armed robbery and possessing a drug of dependence.

The court heard Morgan, aged 20 at the time, left Windana Drug and Alcohol Recovery Centre in Ballarat on March 25, 2019 after two weeks there and argued with his parents who wanted him to stay.

Morgan drank alcohol, became intoxicated and went to Golden Crown Chinese Restaurant to steal money to be able to purchase drugs and travel to his family's home near Geelong.

The court heard Morgan approached the 62-year-old female restaurant owner at the counter with a knife, demanded money and threatened to kill her.

"There is little doubt she was frightened of you, the weapon and your threat," Judge Michael Bourke said.

Morgan stole $500 from the till and caught a taxi to Waurn Ponds.

Four days later, Morgan went to the Ballarat Police Station with his mother and a routine search revealed he was carrying heroin.

The court heard Morgan came from a supportive family and was a qualified chef, but began using drugs in his teenage years and had spent several periods in drug rehabilitation facilities.

Judge Bourke said Morgan had returned to Windana and made further attempts to rehabilitate since he was arrested.

"I have found your prospects of rehabilitation to be good, but they are not certain," he said.

"You have lapsed into crime related drug offences quickly. You need to address your addiction. If you don't address it there will be more than this and you may find yourself spending repetitive periods in custody."

Morgan was sentenced to a two and a half year community corrections order with requirements he complete 350 hours unpaid community work, drug, alcohol and mental health treatment.

"Armed robbery is a very serious offence and usually attracts a sentence of imprisonment," Judge Bourke said in his sentencing remarks.

"The sentencing considerations of general deterrence, the need to condemn the offending and punishment are relevant. The victim was alone, attempting to run and protect her business and was vulnerable."

Judge Bourke said factors against imposing a sentence of imprisonment included Morgan's guilty plea and cooperation with police, otherwise good character, youth, rehabilitation, no criminal history, family support and work capability.

Judge Bourke emphasised the importance of the rehabilitation aspect of the sentence imposed.

"I have been around a long time and I have seen people fail to defeat drug dependence and it ends up disastrous for them, years in jail and worse, often death," he said.

Judge Bourke indicated he would have sentenced Morgan to a nine month term of imprisonment and a two year community corrections order had he pleaded not guilty.