Douglas had a difficult relation with his father and left home when he was 17 years old to go working as a "cowboy" in Hawke's Bay region.
He would live there all the rest of his life, and create a large arboretum, with more than 2,000 different taxa of trees and shrubs.
During World War I Cook fought in Asia, Africa and Europe as a trooper of the Wellington Mounted Rifles and as a gunner in the N.Z.
[3] Cook died in 1967, at the age of 83 years, a "plantsman with the soul of a poet and the vision of a philosopher".
[4] When Douglas Cook arrived at his newly bought land in 1910, he started planting immediately.
[6] In the First World War Douglas Cook served in Gallipoli, Egypt and France.
After returning to New Zealand in 1917 (with a plant of both the red and variegated cabbage tree, that Arthur William Hill of Kew gave him) he started creating his own park.
From 1927 onward, when Bill Crooks got engaged, the creation of the "Parks" started: At the end of his life, Douglas Cook had established an arboretum of international importance.
"After just six weeks a garden was shaping up, and by the end of the first year he had filled sixteen pages of his notebook with details of plantings".
He was afraid that Europe would be destroyed in a new (nuclear) war and saw his plantings as a repository for good garden material.
[14] Douglas Cook had a passion for rhododendrons, and "rhodos" didn't fare well at Eastwoodhill, in the late 1940s.
He and Russell Matthews grasped the idea of creating a rhododendron garden at the slopes of Mt.
Douglas Cook bought the 153 acres (0.62 km2) of land called Pukeiti, and offered the site to the New Zealand Rhododendron Association.
In October 1951 he formed The Pukeiti Rhododendron Trust (by then a group of 24 like-minded people[16]), to which he donated the land.
Membership of the Trust grew steadily, volunteers worked, donations of money, plants and materials flowed in, and Pukeiti, as the gardens have become known, flourished.