The year-long process, outlined in the strategy document Going Local, will see the organisation decentralise functions, giving individual properties more power.
Changes to the organisation's internal structure will involve some redundancies, expected to be concentrated at head and regional office level. It may be months before full details of the plan are known but the "blueprint" of what is needed has now been developed.
Trust communications director Ivo Dawnay said: "The aim of these changes is not to make cuts - the aim is to become a more efficient machine. In effect, one might anticipate that we will see more staff at properties and relatively less in the regions. Our timetable is to have this completed by Christmas."
The charity was to meet negotiators from Prospect Union today (14 May) to discuss the process. A key component of the restructuring will see the Trust's nine English regions slimmed down to six, plus Wales and Northern Ireland.
This involves merging East and West Midlands, merging Thames and Solent with the South East, and merging Wessex with Devon and Cornwall.
Professional Gardeners' Guild chairman Tony Arnold said: "If they are restructuring and we are going to get more gardeners, then that can only be better for the industry."