A total of 6400 plants – 1200 of them harakeke (flax) – went into the ground at Motutapu Island on Saturday.
Around 140 volunteers made a day of it in largely fine weather although recent heavy rainfall through the region meant the ground was often boggy.
The tree planting event was run by local iwi Ngāi Tai ki Tāmaki, kaitiaki for the motu.
Ngai Tai have embarked on a forest restoration programme which is complementary to the work which has been undertaken for many years by the Motutapu Restoration Trust.
They have received funding from the One Billion Tree programme to plant a large area of the Hukunui site above Ōrāwaho (Islington Bay).
The work will greatly accelerate the reforestation of the island, with a wide range of benefits including carbon capture and provision of pest-free habitat for endangered birds and plants.