Inchbald School of Design said the diploma in garden design was the first of its kind to be validated by a university. The course is recognised by the University of Wales.
"The online postgraduate diploma in garden design is aimed at career-orientated professionals, who will study part-time over three years," said a spokeswoman from the college.
"By the end of the course every student will have the knowledge and skills they require to become a professional garden designer."
Students log on to a bespoke website to learn about design implementation, plant knowledge, planting design, design philosophy and theory.
Inchbald School of Design founder and principal Jacqueline Duncan, said: "To be recognised by the University of Wales, renowned for its creative and art-based courses, is a real honour."