Joining a panel of judges who are decades older, he was asked to lend his vast horticultural expertise to judge contenders of the Betty Hart Memorial and Peter Lawrence Challenge trophies.
But he was barred from considering his own pride and joy - the eye-catching gardens at Avon City Motel, on Main North Rd, Redwood, owned by his parents won the Galey Trophy - for colour impact.
These gardens were also partially responsible for the production of nearly 60,000 swan plants and seeds he donated to people who also desired to save the monarch butterfly population.
The year 10 St Andrew’s College student helped judge about 20 gardens across the city, covering secret gardens and retirement villages.
“I feel really lucky and proud because I’m not the normal person to be a judge,” he said.
But Sea-am was prepared, knowing “a lot for someone my age.”
“I didn’t want to judge them because they were all so good, but I knew I had to do the job, I couldn’t be too kind on them.”
Trevor Tubman, the association’s head of media and events, said the 14-year-old was the youngest judge the competition invited to participate “by a long shot.”
The motel, where he got to know Sea-am, often won awards, so Tubman got thinking.
“I suggested to his dad that he comes along to see what we do and how we do it, and he jumped at the opportunity. He’s got wonderful plant knowledge - it’s amazing the amount of knowledge he has,” he said.
Sea-am has been pottering about the garden since he was 2-years-old. Born opposite the ocean, his name in reverse - “I am the sea” - roughly reflects his Kaikoura upbringing.
Aside from swan plants, he favoured butterbeans and tuberous begonias.
“It’s been longer than I remember because I can’t remember when I started.”
His father Terry reckoned the family got his son into it, being keen gardeners themselves.
Said Sea-am: “Our motel is really mainly about our garden, without it, I wouldn’t have done it as much.
"In Kaikoura when I was young, I did a lot of vegetable gardening and I was really proud to pick all the veges and give them away.”
Knowing they were plummeting towards extinction due to factors like climate change and farming, he planted swan plant seeds to encourage monarch butterflies to reproduce.
Since then they have grown in size and number, attracting hundreds of butterflies to the motel gardens and at the original Kaikoura garden.
Caterpillars love to eat swan plants and later use it to transform into a chrysalis before hatching into butterflies.
In three years, he has donated thousands of plants and seeds. Each pod sometimes contained 80 seeds.
“Butterflies can smell the scent of swan plants from over two miles away.”
Sea-am may be the youngest gardening judge, but he also might be one of the youngest to keep the tradition of organ playing alive at a time when the number of players dwindles nationwide.
Through this, he learned how to play the organ at the Transitional Cathedral from Dr John Linker and StAC music teacher Brian Botting, and once sang for Prince Charles with the Christchurch Cathedral Choir.
Music runs deep in his blood - his father plays the accordion and harmonica and a great-great-uncle composed Sir Edmund Hillary’s wedding music.
Between gardening, sport, homework and flying lessons, Sea-am wouldn’t give any of it up, even if it means being out of the house 12 hours a day.