Garden Organic chief horticultural officer Bob Sherman, RHS horticulture director Jim Gardiner and GCA inspectors Ian Boardman, Andy Campbell and Roger Crookes will also speak and show their garden centre audits from 2011.
Catering expert Chris Brown will talk on how to create a quirky cafe to beat the corporates.
Diciamo MD Mario Dolcezza and Retail Acumen MD Clare rayner will also speak on improving your business.
There will also be updates from LOFA and Garden Re-Leaf. Associates night will be on Monday night, when retailers can meet suppliers.
The 24 January line-up includes Ruxley Rose and Christmas results and talks on mobile advertising, improving your business culture, the economic outlook, positive thinking, customer service and a five minute presentation from teams of Westland Horticulture's 'rising stars'. Comedian Milton Jones is after dinner speaker.
On 22 January the GCA will hold an Its a Knockout competition at the hotel.
The event is held from 22-25 January at Heythrop Crown Plaza near Chipping Norton in Oxfordshire 0X7 5UE.