The Young Horticulturist of the Year judges were RHS executive vice-president and former Askham Bryan student Jim Gardiner and TV gardener David Domoney.
The winners were the level 2 horticulture, floristry and arboriculture students. The northern heat was won by Adam Robinson, who is studying a foundation degree.
Around 80 students were involved in the day at the York-based college under the theme "Tour de Yorkshire". In July, the Tour de France starts in the county.
Gardiner said: "The industry needs around 3,000 new entrants coming over the next six years and that's a real challenge. Courses such as at Askham Bryan are vital to help address that shortage."
Last year, the college announced a £34m expansion plan that would see student numbers across horticulture, agriculture and equine and animal care rise from 2,000 to 5,000.
