Dominic Doyle, 21, was an innocent bystander who was stabbed during a night out in Denton on 7 June 2015.
His mother, Rhian Jones, is supporting a week-long knife surrender by police to get knives off the street.
She said: "I'm hoping that if I can help somebody else, just one person, then I feel like I've done my bit."
"He was my life, he was my only child and I just exist," she said.
"It's changed me totally and everybody around me. He was my life.
"I just want people to speak to their kids, be honest with them, be open, talk to them, have the conversations about what's right and what's wrong."
Colin McDonald was jailed for 15 years in February after being found guilty of Dominic Doyle's manslaughter following a trial at Manchester Crown Court.
The "Bin the Blade" campaign by Greater Manchester Police sees dedicated bins placed into 11 police stations in Greater Manchester.
Knives - including illegal weapons or any other unwanted bladed instruments - can be dropped off in the bins safely and anonymously until 27 November.
Det Ch Insp Debbie Dooley said: "Knives pose a serious risk within our communities and the more we can take off our streets, the greater chance we have of saving lives."

The Guardian reported that the victim had been held up at gunpoint while enjoying a night on the town in the early hours of Tuesday morning.
A spokesman for the British Olympic team confirmed an "incident of theft", adding: "All members of our delegation, including the individual concerned, are accounted for, and are safe and well."
GB took 366 athletes to Rio.
They have since been reminded of security protocols including not to wear official GB kit outside of the Olympic Village and not to take local taxis, according to the Guardian.
It said a letter from GB officials stopped short of issuing a curfew on athletes, but warned them not to carry any valuables and to inform team management of any plans to stay in Rio overnight.
United States swimmers Ryan Lochte, James Feigen, Gunnar Bentz and Jack Conger have claimed they were robbed in a taxi at gunpoint in Rio on Sunday but police have queried their accounts.
The mother of a man who died from stab wounds after a brawl outside a pub in Greater Manchester has said "life will never be the same" without him.
[NEXT_CONCEPT]
A Team GB athlete has been robbed while returning to their accommodation at the Olympic Games in Rio.