Log in

Editor's Picks

Emory oak near Young, Arizona © Nanebah Lyndon
Emory oak acorns are a critically important commodity for...
Website Editor | Feb 12, 2021
Ecological Landscape Alliance
Murphy Westwood and Tim Boland presented on oak diversity...
Website Editor | Feb 12, 2021
Keiko Tokunaga's Illustrated Fagaceae
Shaun Haddock reviews Keiko Tokunaga's latest book.
Shaun Haddock | Feb 09, 2021

Plant Focus

Quercus texana New Madrid acorn
Disentangling the cultivar published as Quercus texana ‘New Madrid’

Cork Wars in World War II: Oaks, Espionage and National Security

PDF icon Full text available for IOS members only. If you are a member, you need to log in.

To create an account click here; if you have already registered, click here to become a member.

Individual articles can be purchased for U$S 10. If you would like to purchase an article, email a request to website@internationaloaksociety.org

David A. Taylor

Published May 2019 in International Oaks No. 30: 295–300


This paper shares a compelling piece of oak history and California history. In the 1940s, when cork was a modern material crucial to America’s war effort, youth clubs and state governors were planting Quercus suber (cork oaks) to make the country free of dependence on foreign sources.
By 1940 the United States imported nearly half the world’s production of cork, for industries ranging from bottle caps to automobiles, flooring, various forms of insulation, and bomber airplanes. When Germany blockaded the Atlantic trade, the shortage of cork from Europe became a threat to national security. Then when a factory fire in Baltimore stirred an FBI investigation for sabotage, the entire industry was pulled into the war effort, from corporate espionage in Portugal to a nationwide tree-growing campaign.
The paper draws on research from the author’s new book, Cork Wars: Intrigue and Industry in World War II (Taylor 2018). It looks at the system from Portugal’s montado oak forests to the American tree-growing campaign, in which a dozen state governors brandished shovels to promote a patriotic cause. In addition to telling this story, the paper shares the discovery process and research process, from conducting survivor interviews to uncovering declassified records in the National Archives.


Quercus suber, Crown Cork and Seal, Woodbridge Metcalf, McManus Cork Project