Republished from Wanaka App 2nd June 2026
The Upper Clutha Wilding Tree Group (UCWTG) has explained why dead pine trees remain on Little Mt Iron after the group’s trained volunteers worked with private landowners to remove wilding pines on the reserve.
UCWTG member Jenny Cleland told the Wānaka App the group wants to reassure residents that “the drill and fill method of killing pine trees is the most appropriate for these particular trees and is recommended by FENZ [Fire and Emergency NZ]”.
“The easiest and cheapest way to deal with these large pines is to drill holes into the tree trunk and fill them with chemicals,” Jenny said.
The trees die standing and break down over time with branches dropping around the base - avoiding the hazards of felling and minimizing damage to surrounding native vegetation.
The live/green trees are more flammable than dead ones because they contain highly flammable oils, Jenny explained.
“The fire risk is reduced as there is not a large fuel load on the ground that you would get with felling and leaving the tree there.
“Leaving these huge pines would mean that in the event of a fire, they would act as candles and throw flames and sparks ahead of the fire in the wind, thus spreading it more quickly and potentially endangering more properties downwind.”
The ‘drill and fill’ technique must only be carried out where there is no risk of trees dropping on to people or any built infrastructure or over a property boundary, she said. Where this is an issue arborists or qualified chainsaw contractors would need to fell the trees and deal with the tree limbs and waste on the ground.
“The main negative with this control method is that we have to look at these decaying trees for 5-10 years… It really is a short term visual pain for the long term gain.”
Jenny said the dead pines “serve as a reminder that it is much easier to deal with wilding pines while they are small prior to coning (producing seed)”.
“The take home message is that we need to keep Mt Iron free of spreading pines that increase the fire risk for residents living there.”