Garden Centre Association (GCA) chief executive Gillie Westwood said previous talks about making the association the "gold standard" of HTA membership using its inspections could be revived so the two organisations work to "complement" each other.
Meanwhile, HTA-run Association of Professional Landscapers (APL) chairman Mark Gregory reiterated his desire for the APL to join with fellow trade body BALI: "The industry has to get back to one body and I will be proactive in promoting the move."
Garden Industry Manufacturers' Association director Neil Gow said: "There have always been areas where we'd like to work more closely with the HTA. We have good relations with many groups such as the Leisure & Outdoor Furniture Association and the GCA but none of us know what the future holds for the HTA until there is a replacement director-general."
British Protected Ornamentals Association treasurer Simon Davenport said he will raise the issue at a management meeting this week.