Morris, who is handing over to HTA horticulture manager Raoul Curtis-Machin after six years as Grow chairman, said the industry needs to work together to promote the portal. Around 40 horticulture bodies set up Grow in 2006. HW hosts the site.
Morris added: "We don't need another Grow, we have already got it. We don't need 30 different institutions doing it themselves. We need to get behind the one we set up. We don't need competing organisations setting up their own schemes."
Grow is "being perceived as the Leigh Morris Institute." He added: "Curtis-Machin was on the steering group at the start and it's strategically beneficial for Raoul to chair."
Grow is seeking applicants to make a £10,000 film to encourage 11-18-year-olds to make a career in horticulture - see www.thesmalls.com/pitch-room/grow. The entry deadline is 21 March. Morris said the film should be designed to make people "laugh or cry".
On the handover to Curtis-Machin, Morris said the Global Strategy for Plant Conservation is the blueprint for young horticulturists to find out how they can change the world through their careers. Some of his proudest achievements were helping set up botanic gardens in war-torn northern Iraq and Haiti, he added.