As part of his new role he will have a special focus on championing horticultural science and will work alongside other RHS ambassadors and the horticulture industry to raise the profile of careers in horticulture.
To launch his role Wong will ‘take over' the RHS twitter feed on 21 March 2014, during National Science Week. He will celebrate why horticultural science is "amazing" to the RHS' 54,000 followers and answer their questions.
Alan Titchmarsh became the founder RHS ambassador in 2013.
Wong said: "I'm incredibly proud to be asked to do such important work, not just for the RHS, but for all of UK horticulture.
"I know from my own experience of teaching young people ethnobotany there is a real appetite out there for horticulture, but there are still many people of all ages who don't fully appreciate the importance and relevance of horticultural science to their lives. Through this role I hope to play a part in changing that."
RHS head of science Dr Alistair Griffiths said: "We are delighted that James has agreed to work alongside us to promote horticultural science and help to inspire a new generation of botanists and horticultural scientists.
"Botany and horticultural science provides us with knowledge that benefits people throughout the world and contributes in many ways to the sustainability and cultural heritage of our planet. It also helps us pollinate our trees, manage pests, improve human, animal and plant health, facilitate trade, respond to climate change, conserve our environment, and much more.
"We're really proud of the scientific work we do at the RHS. No other charity invests as much of its resource into the scientific study of gardening, garden plants and horticulture. Having James on-board, with his botanical knowledge and infectious enthusiasm, means we are in a great position to amaze and inspire others about how beneficial and satisfying a career in botany and horticulture can be."