Welch joined the domestic lawn-care company on 26 October, seven months after his controversial sacking from the top job at Wembley Stadium.
The former Groundsman of the Year winner was dismissed from Wembley due to intense media pressure following negative comments from top football managers.
But he was widely backed within the industry, with the Institute of Groundsmanship slamming the decision to replace him.
TruGreen marketing manager Hannah Banfield said Welch had been appointed to head up the lawn-care network from a technical advice point of view and would bring extensive expertise to the role.
See HW, 13 November for more.
Subscribe to Horticulture Week for more news, more in-depth features and more technical and market info.