John Theophil Strentzel (29 November 1813 – 31 October 1890) was a Polish-born physician who gained fame as a pioneer in the area of experimental California horticulture. He is best known as the father-in-law of writer and environmental activist John Muir.
Born in Lublin, Poland into a wealthy family, Strentzel was forced into exile after his participation in the Polish revolution of 1830. In 1840 he emigrated to the United States of America, settling in Texas. It was there, in 1843, that he married his wife, Louisiana Erwin. In 1849 he made his way out west to California, eventually settling in the state's central valley, along the Merced river. Illness and flooding of his home along that river forced him to move again, this time settling in the Alhambra Valley, a bucolic valley located just south of the city of Martinez, California. He purchased twenty acres, called for his family, and set about establishing a long-dreamed of horticultural business. Years later, he was recognized as a foremost expert on California's budding horticultural industry.
In 1880, Strentzel's good friend and companion, John Muir, married Strentzel's daughter, Louisa. He allowed the earliest form of the Martinez Library to use one of his buildings with no charge. In 1882, Dr. Strentzel constructed a 10,000 square foot home on a knoll above his vast orchards; John and Louisa Muir moved into the home after Dr. Strentzel's death in October 1890, and it is now preserved by the National Park Service as the John Muir National Historic Site.
John Theophil Strentzel is buried in a small, private cemetery, along with other family members (including John Muir). The cemetery, now owned by the National Park Service, is located near the family's Alhambra Valley home.
- "FindAGrave Entry & Photo of Strenzel's Headstone". FindAGrave.
- "Dr. John Theophile Strentzel". United States Department of the Interior. Retrieved September 28, 2012.
- Hubert Howe Bancroft. Chronicles of the Builders of the Commonwealth, Volume 3.
- "Martinez Walking Tour - Martinez Library". Martinez Historical Society. Retrieved 13 January 2017.
- "John Muir National Historic Site Museum Collection". National Park Service. Retrieved September 28, 2012.