The recreational photographer was one of four winners announced at the garden information centre on Saturday morning.
His photograph of the garden's aviary won the open section for people aged 15 or more years, while another two of his images were commended and highly commended in the plant category, won by Tara Jahn-Werner.
A member of the Dunedin Photographic Society, Mr White said photography was a hobby which demanded a certain level of investment.
''Everything has to be upgraded. You become a bit of a photography nut.''
He and other winners took home plants and certificates for their work, which will be on display at the garden information centre until May 21.
Lena McNaughton (13) won the plants category for children aged 14 and under, and she was highly commended in the open section, won by Ruby Harris (13).
About 200 people entered the competition, organised for the garden's 150th anniversary celebrations this year.
All photographs had to be taken within the garden, ''The main point of it was to draw people into the garden and get them engaged and looking at the garden in a different way ,'' collections supervisor Barbara Wheeler said.
Judges said the standard of entries was excellent, making it difficult to select winners.
Visitors to the garden can view the exhibition until May 21 and vote for their favourite image, for a people's choice prize to be announced this month.
