Three new modules have been added to the GCA's e-learning initiative Garden Retail Online Workshops (GROW).
The scheme helps member garden centres, of which there are nearly 200, keep their customer service at the highest standards. The three new modules are wild bird care, starting a new lawn and soil types.
There are now 49 modules available as part of the e-learning initiative which, according to interim GCA chief executive Iain Wylie, has "really taken off".
"We understand a lot of our members don't have the time or resources to fully train all of their staff," he added, "so we came up with this idea to keep their customer services standards at the highest level possible.
"We plan to keep on adding further topics that will focus on all areas involved with running a garden centre. We are currently working on two further lawn-care modules, which will be available later this year."
GROW is available to all GCA members, with the aim of giving them an opportunity to train all staff and ensure they have a basic horticultural understanding.
Mr Wylie added: "All our members who have signed up to GROW so far have been incredibly impressed and enthusiastic so we want to remind those that have not yet registered that they can sign up now to get the full benefit from all the modules."