In the North Island, settlers burned native forests to make farmland for sheep and cattle.
Underscrubbing and felling
The work began with underscrubbing – cutting down the creepers and shrubs of the understorey. After these had been left to dry, they became fuel for the main fire.
The standing bush was then felled and also left to dry. Some settlers thought that felling all the big trees produced better results. However, in wetter districts the largest trees were left standing as they became waterlogged when felled and did not burn.
Underscrubbing and felling was a winter job, and the fallen trees were left to dry over summer.
Burning and reburning
Burning was done at the end of summer or in early autumn. A successful burn cleared off the smaller trees and shrubs, but left a landscape of blackened stumps and logs.
Grass seed was sown on the ash, which at first proved to be highly fertile as it contained nutrients mineralised by the burn. But as the initial fertility declined, fern and scrubby weeds invaded the oversown pastures. Further burning was an important way to remove the logs and stumps left after the first burn, and to clear off the regrowth of fern and weeds.
Controlling bush fires
Managing fires in bush country was hit and miss. A dry season was ideal for burning off felled trees and scrub, but nearby standing bush became tinder dry, and it was not uncommon for fires to get out of control.
Harry Combs, who grew up in Hawke’s Bay’s Forty Mile Bush, described a bush fire in 1885:
Tall trees, like tremendous torches, are ablaze from the ground up. The whole world is on fire. And then [after 10 days] the rain! The blessed, glorious rain … The long fight is over. Where magnificent trees once stood there are now scarred and twisted and gaunt trunks, and pile upon pile of charred remains … as far as the eye can see. 1
Houses and settlements built in the clearings were vulnerable if a fire took hold. During a widespread drought in the summer of 1885–86, houses, businesses, farms and thousands of acres of bush in southern Hawke’s Bay and Taranaki were destroyed by bush fires.
Burning was essential in the effort to turn the North Island fernlands into grazing land for sheep and cattle. The process was known as fern crushing.
In the autumn the fern on a selected block of land was burned and the ground sown with grass and clover seed. A week or two later, as many sheep as possible were put on the land to trample the sprouting fern fronds. In some areas this had to be repeated every five years or so, as the fertility of the land declined and the fern again took hold.