Intrigued by the differing opinions on the source of our modern day domestic apples, he embarked on a project to discover and record their origin and geographical spread over time.

[4][2] Juniper carried out fieldwork in Kazakhstan to explore the hypothesis that modern apples originated there and postulated that they were brought into popular use alongside the domestication of horses.

As part of his research into the origins of the apple, he established a specimen orchard there, to provide the collection of trees for his DNA analysis.

[citation needed] With co-author David Mabberley, Juniper wrote 'The Story of the Apple', which documented his research, travels and conclusions.

[citation needed] The Carnivorous Plants was authored by Juniper, Richard J. Robins, and Daniel M. Joel.