Last year's election gave the Greens their best ever result and they're aiming at doing even better in 2014.

"Growing the Greens" is the theme of the party's annual conference this weekend, the first get-together since it brought 14 MPs into parliament last November.

Since then it's built a media team that's often quicker and smarter than Labour's, its co-leaders have pushed their profiles way up the scale and policies have been sharply defined.

"Our focus moving forward is expansion," says co-leader Metiria Turei.

"Since the election we've been developing our team and taking on a bigger role in opposition."

Russel Norman, the party's other co-leader, says the 2011 election campaign increased membership and the number of volunteers it put in the field.

"That increased the number of New Zealanders we directly communicate with," he said.

"This term is about maximising the participation of those people in the political process."

He sees campaigning on key issues as vital to being an effective opposition and says the fight against asset sales has brought opposition parties together.

The Greens have worked with the government since the election, through a memorandum of understanding, on projects like home insulation and the clean-up of toxic sites.

There were plans to expand it but National became wary of the Greens' growing influence in parliament and Dr Norman's trenchant attacks on core government policy.

The government decided there wasn't going to be any further co-operation with the feisty opposition party and two months ago said there wouldn't be any more joint projects.

That hasn't bothered the Greens who are setting their own agenda, which will be explained to delegates and supporters during the three-day conference in Lower Hutt.