Restoring Northern Rata to Waiheke

"This species was once a significant component of the Southern Ruahine forest but possums have lead to its virtual extinction there, while many other areas are under similar threat. Over much of the Central North Island, if you want to see a Northern rata just look for a dead tree"

From 'Pohutukawa & Rata - NZ's Ironhearted Trees'
by Philip Simpson, a founding trustee of Project Crimson

GENERAL INFORMATION

Typically starts life as an epiphyte high up in the forest canopy, establishing itself on a host tree then sending down roots to form a supporting trunk. The trunk is not a true stem but instead a number of fused roots. Northern rata trees can grow up to 25 metres tall, with a trunk of up to 2 metres in diameter, although epiphytic rata rarely grow larger than their host. The host can be any of a number of different species although the foster tree of epiphytic rata is commonly rimu.


Metrosideros robusta

The small leaves are dark green and leathery, often with an indented tip, stems are square. Small wind-dispersed seed are produced in autumn. Natural regeneration of Northern rata can take a minimum of 45 years just for a descending root, 20m up in the canopy, to reach the forest floor. It thrives in the regenerated forest of Kapiti Island due to the absence of possums.

PLANTING TECHNIQUE

Northern rata can be planted in the ground rather than in a mature tree, but require very good drainage. On clay soil plant shallow and heap up with leaf litter to cover exposed root ball. Position where they get a good degree of sunlight but shaded during the hottest part of the day, so are ideally placed on forest margins, not under closed canopy.

With thanks to Stephen Benham, DOC Biodiversity Ranger, for his advice