Matthew Ellis and Darren Brooks from Notcutts Garden Centre and Julian Beer from the Van Hage Garden Company won scholarships worth £2,000.
They joined the cream of retail management for a week at the Oxford Summer School, held at the city's famous university.
Talks by Liberty chairman Marco Capello and Fortnum & Mason managing director Beverley Aspinall headlined the event.
Ellis said: "I am especially interested in learning more about marketing and merchandising."
Brooks said he was keen to improve leadership skills, network and learn from talking to other retailers.
Beer added: "Networking with other independent retailers will help me bring revitalised energy to my employer."
Sector skills council Skillsmart Retail and the Retail Trust offered 11 scholarships for the event, run by the British Independent Retailers Association.
The bursaries are available to retailers employing fewer than 1,000 staff, with the aim of helping independent businesses.