Visitor numbers were up by 40% to 130 buyers and other visitors, while exhibitor numbers reached 88, up from around 70 at past fairs.
The event was held in hall 1 of Stoneleigh Park for the first time and the move was greeted with a positive reaction.
Organiser Geoff Caesar said: "This has been our biggest event by far and we hope it shows that with more support from growers and retailers we are becoming a key way to meet growers and buy plants in the UK."
Trade in the market place trolley fair was steady and individual exhibitors reported a strong showing.
Allensmore Nurseries George Price said: "This was the best fair so far. We had buyers on our stand continuously for the first three hours. There was a great upbeat feel to the day with all buyers positive for the forthcoming season. Buyers who have not attended for a while now are missing a major plant buying event."