Volunteers have planted 3000 native plants on the now pest-free islands of the eastern Bay of Islands in the past month.
The latest plantings have focused on Urupukapuka and Moturua, the two largest islands in the Ipipiri group.
In May, 105 volunteers planted 1950 trees and shrubs at Urupukapuka's Ihumatea Bay, then 660 went in at Entico Bay.
In the latest planting, 360 natives were put in at Army Bay on Moturua Island.
Since the first seedlings went into the ground on Waewaetorea Island in 2003, more than 15,000 native shrubs and trees have been planted on the island reserves of the Ipipiri islands - all grown by the Kerikeri Shadehouse Volunteers.
Rod Brown, a Kerikeri resident who drives the shadehouse project, said the group had been planting on Urupukapuka for the past four years, with significant numbers of pigeonwood, puriri, kohekohe, taraire, nikau, karaka, kowhai and rewarewa now in the ground.
The young trees were helping to enrich food sources for the increasing numbers and species of birds living on the island since rats and mice were eradicated in 2009.
Mr Brown said 40 native plant species had been planted at Entico Bay so far and a total of about 3400 plants on Urupukapuka.
A significant infestation of moth plant on Moturua Island - a pest plant that threatened developing native forest - had also been dealt to by a group of volunteers, Mr Brown said.
The planting project is part of Project Island Song, which aims to restore the original flora and fauna of the Ipipiri islands and is driven by the community group Guardians of the Bay of Islands.
Guardians chairwoman Fleur Corbett said controlling pests and weeds, planting trees and bringing back the birds were the three legs on which Project Island Song stood.
"With the noticeable increase in tui numbers on the islands it's great to see so many native plants going into the ground to provide food for the birds into the future," she said.
Transport for volunteers to get to the planting days was provided by Fullers and the Department of Conservation, with picnic lunches contributed by Scenic Circle.