The average age of city residents is 33, one of the lowest in New Zealand, yet there were no Palmerston North city councillors aged less than 30.
Swarbrick said all the young candidates were invited to the forum, Green or not, because it made it more interesting to hear a diversity of views.
William Wood, 19, and Orphee Mikalad, 30, along with Rozenberg and Speller took up the invitation, but Nikita Skipper put in a late apology.
Wood said it looked like voter turnout for the by-election might be as low as 28 per cent.
That was because so many young people did not know what the council was, and because councillors were not engaging successfully with their community.