In 1845, the Leighton Hall, Powys estate was purchased by the Liverpool banker Christopher Leyland. In 1847, he gave it to his nephew John Naylor (1813–1889). Naylor commissioned Edward Kemp to lay out the gardens, which included redwoods, monkey puzzle trees and two North American species of conifers in close proximity to each other – Monterey cypress and Nootka cypress. The two parent species would not likely cross in the wild, as their natural ranges are more than apart, but in 1888, the hybrid cross occurred when the female flowers or cones of Nootka cypress were fertilised by pollen from Monterey cypress.