The National Apprenticeship Awards, now in their 12th year, celebrate the success of the country's top apprentices and their employers.
Cain has been fundamental in developing John O'Conner's apprenticeship scheme and believes in promoting opportunities for both new applicants and young employees.
He commented: "I am truly honoured to win this award. My City & Guilds apprenticeship with Sunderland Parks Department has been the foundation for over 30 successful years in the horticulture industry, providing personal and professional fulfilment.
"My progression is a testament to the potential of apprenticeships - evidence a [university] route is not the only option to exceptional careers."
Cain added: "My goal is to not only promote apprenticeships but also the extensive wider career opportunities open after the initial scheme and will continue to pass this philosophy down to my team and wider network."
The East of England winners and highly commended entries were announced on 27 October.
Following the regional ceremonies, the winners from each category in all 11 areas of England will have their entries sent for national judging, and three from each category will be selected as national finalists.
The national award winners will be revealed at a ceremony held in January 2016 at the Grosvenor House Hotel in London.