I just reread John Sherwood's THE MANTRAP GARDEN. I dug out this vintage book because of our garden-related mysteries feature, and it holds up really well. While the book is set in and around a stately home garden, and in many ways it is still a cozy, in other ways it is unexpected.
For one thing, there is a fascinating section that flashes back to WWII and the work at Bletchley to break the Enigma cipher. I've read other books about this and I'd forgotten the Enigma code played a part in this mystery. There is also industrial espionage on an international scale.
The garden featured in this book was originally designed by Gertrude Jekyll, and there are many quotes from her books scattered throughout.
Although the book mentions Gertrude Jekyll designed in the United States, it doesn't mention that she never actually visited the USA. She only designed three gardens in this country, and her plans were based on detailed plans of the garden sites.
Gertrude Jekyll - Gardens in America
lists the following U.S. gardens:
https://gertrudejekyll.co.uk/gardens_in_america/#:~:text=She%20wrote%20articles%20for%20American,influential%20in%20garden%20design%20circles.&text=During%20her%20later%20years%2C%20she,by%20meticulous%20attention%20to%20detail.
Gertrude Jekyll’s American gardens were as follows:
1914 Elmhurst, Ohio
1925 Cotswold Cottage, Greenwich, Connecticut
1926 Old Glebe House, Woodbury, Connecticut, which was restored during the 1990s and can be visited.
It's a well-kept secret that she also designed a garden at the Groesbeck Estate, now part of the Cincinnati Nature Center. Although her original plans have been saved for posterity, the garden she designed was never implemented because the site was so steep it wasn't considered feasible. Elements of her design, including stone paths, were installed and have been preserved.