The aim is to reduce time spent by staff on back-office functions, so they can spend more time with customers to improve service and sales. All staff will take part in lean awareness training and 30 lean champions will be appointed to help with the implementation.
An initial trial at the Woodbridge centre in November identified 1,591 hours of wasted time that could potentially be saved.
Garden centres managing director Michael Cole said: "The initial trial project was illuminating and showed that by looking in detail at a process, significant efficiencies could be achieved."
Notcutts' lean project manager Nigel Coombs said that from the first trial it was clear huge benefits could be achieved by reducing unnecessary processes.
HTA business development director Tim Briercliffe said: "Garden centres need to become leaner to keep ahead. The HTA lean programme enables garden retailers to focus on areas that can be made more efficient and free up staff time."