Mr Quinn said that the productivity of the finalists' gardens is taken into account in judging, along with innovation and crop abundance and quality.
Mr Quinn said the Featherston garden was the only garden in the contest, as far as he was aware, that also had an operational hydroponics unit.
Sally Addis, garden centre manager at Mitre 10 Mega in Masterton, was also on hand for the judging at the southern Wairarapa school yesterday and teacher Felicity Pickering, who was central to the establishment of the garden, accepted prize packs of gardening books and equipment and a finalist certificate that was donated by Mitre 10 Mega and Tui Products.
Winners of the garden challenge will walk away with gift vouchers of up to $1000 each and a range of garden products.
Winners will be announced this month.