The decision to remove the two Norfolk pines had been a difficult one for the St Luke's committee and the community, chairman and vicar Rev Tim Hurd said yesterday.
The Norfolk pines, now 25m high and within 2.5m of the church, will be taken down by an experienced arborist from next week.
Depending on weather, the work could take up to three days.
The timber will be used for memorial furniture inside the church and a plaque will be mounted on the north porch depicting the pines and their place in Oamaru's history.
Over recent decades, damage to the church's porches, paths, drains, roof and stonework had been noticeable. The impact on the church's foundations cannot be ascertained.
The trees were planted in 1878 to mark the deaths of Bishop Selwyn, first Bishop of New Zealand, and his friend Bishop John Patteson, killed seven years earlier in Melanesia.
''We are deeply attached to these historic trees, beautiful in their own right and of real significance for the Anglican leaders they memorialise.
''But we are mindful that they are simply, at their size, in the wrong place.''
The arborist's report confirmed neither the selection of tree or their proximity to the church was appropriate.
While Norfolk pines lived to 150 years old, they were coming to the end of their lifespan and it was considered prudent to remove them now in ''a carefully-managed manner''.
