The following links may useful:-
Ashburton Food Festival:- https://facebook.com/events/578483705642578
Nourish Festival at Bovey Tracey :- http://www.nourishfestival.org
Rare Plant Fairs :- http://rareplantfair.co.uk
NCCPG :- http://www.nccpg.com
Royal Horticulture Society :- http://www.rhs.org.uk
Barnstaple Food Festival :- http://www.foodfest@barnstaple.co.uk
Plants for a Future :- http://www.pfaf.org