Haskins chief executive Julian Winfield said: "The GROW e-learning is one of the best initiatives we have ever had in our industry.
"It really helps independent garden centres to train their staff to a high standard and allows senior members of the team more time to help our customers with their gardening needs."
GCA chief executive Iain Wylie added: "We launched our first 10 modules in January and we are pleased to see it has received such a great reception from our member garden centres.
"We understand a lot of our members don’t have the time or resources to fully train all of their staff, 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 have recently added health and safety and food safety modules to cover levels one and two. This includes 35 subject modules, making a current total of 45 within the GROW scheme.
"More modules will become available throughout the year, including wild bird care, soil types and starting a new lawn. Later in the year we will have categories such as furniture and barbecues, as well as customer care."