Collections supervisor Barbara Wheeler said the garden regularly received requests from overseas students and staff from other botanic gardens looking for an internship.
In 2003, three requests were received, but more recently it had jumped to about 15 a year, she said.
Horticulturists enjoyed learning about botanic gardens in different parts of the world and she tried to accept as many requests as possible.
"I'd like to think people look at the [Dunedin] botanic garden and think: `That's the place to go'."
Placements varied in length from two weeks to 12 months, depending on the person's ability to survive working voluntarily for the garden.
Many students came to complete a section of their qualification, while others would simply do gardening work.
The relationship between the garden and interns was "win-win", Ms Wheeler said.
The garden benefited from their helping hands and different knowledge base, while the interns were able to learn about native flora in another part of the world.
The four Europeans working in the garden at present became aware of it by word-of-mouth.
Margreet Scholten, of HAS Den Bosch University in the Netherlands, said her qualification required her to complete a traineeship overseas and she wanted "to go as far as possible".
When she arrived, she was surprised to find the Dunedin Botanic Garden was "so huge" and "hilly".
There were no gardens like it in her home country.
"It's a really good opportunity to extend your skills.
"They [garden staff] give you the opportunity to learn."
