Mrs Kelly said it was important a school's board reflects its community.
"A good balance of gender, ethnicity and skills around the board table will influence and support educational opportunities for each and every student in our schools."
In a recent survey of board chairs, 25 per cent said their current trustees will be seeking re-election.
Another 60 per cent said less than half the incumbent trustees would be restanding for election and 78 per cent said they were confident of receiving enough nominations to fill their board positions.
Mrs Kelly said all parents of students enrolled in a New Zealand state or state-integrated school were eligible to nominate themselves or someone else from the community for election to a school board.
Mrs Kelly said each school decided the constitution of its board, which could have from three to seven parent representatives.
She said each board needed an average of five parent representatives. Also on the board were the principal, a staff representative and a student representative for schools with Year 9 students and above.
"You can look outside your pool of parents for people with governance experience or people who want to help lift student achievement, and we want as many people as possible with those skills and goals to step forward."