Joan K. Michaelson, 81, biochemist, Chester County open space advocate, Christmas tree cultivator, and self-described philosopher, wife of the late Thomas C. Michaelson M.D., of Chester Springs, PA, passed away on Wednesday, February 17, 2016 after a long decline. Born on October 13, 1934 in Wilkes Barre, she was the daughter of the late Leo and Ann (Diskauski) Knoll, the gardener and cook, respectively, at the estate of a Woolworth's heir in Glen Summit, PA.

Mrs. Michaelson received her degree in medical technology from Penn State University in 1957. She worked at Merck Sharp and Dohme, where she helped to develop the important diuretic, ethacrynic acid, and rescued a white lab rat named George, who rode on her shoulder on her drives to work.

Joan was active with the West Vincent Township Planning Commission, the Phoenixville Hospital Auxiliary, and the Green Valleys Watershed Association. She founded Windridge Farm Christmas Tree Plantation at the age of 60.

She was extremely proud that she climbed Mt. Kilimanjaro at the age of 62.

Mrs. Michaelson is survived by her children: Thomas Erik Michaelson M.D., husband of Susan Troxell, of Philadelphia and Holly K. Michaelson M.D., wife of Lora Talbot, of Conway, MA; brother, Leo J. Knoll, Jr., of Andros Island, Bahamas; and grandchildren Peter, Zachary, Devon, and Thomas.

A memorial gathering will be held in future at the convenience of the family.

Arrangements are being handled by the Campbell - Ennis - Klotzbach Funeral Home, Inc., Phoenixville, PA. Condolences may be offered online at www.PhoenixvilleFuneralHome.com.