"We feel very privileged and proud.
"I think the win is a reflection of everyone in the company and all the hard work we all put into it."
Hamish said the company entered just before entries closed, and admitted there may have been a touch of beginner's luck involved.
"We thought about it, [entering] then we didn't know, then we thought 'why not' and it all went from there."
The business was formerly known as Evergreen Soil Conservation, established in 1969. Hamish and wife Sally bought the business in 2003, renaming it to Evergreen Landcare sometime later. Sally works as the accounts manager. Their son Ben joined the family business late in 2010 and since then has played a major part in its development.
Hamish said since the rebrand the company had expanded and now had more than 40 employees, some based in Auckland and Christchurch.
He said, in simple terms, the company worked on land restoration and improvement.
As for the business's secret to success, Hamish said teamwork among staff and developing enduring relationships with clients was key.
Ben said he was "stoked" with the win.
"It was a good night, a bit of surprise, but it was good to see all our hard work recognised."
The night's other big award, the Business Person of the Year, went to Deryck Shaw of APR Consultants.
Mr Shaw went to the awards to support St Chad's, who were finalists, and had no idea he was in the running for an award.
"It was a surprise really. I was there to support some of the finalists and when the judges were reading out the achievements of the person who won [Business Person of the Year] I thought 'that sounds a bit like me' - then they read my name out. It was a big surprise, I was quite humbled."
Mr Shaw said he couldn't have won without the never wavering support of his family.