The island of Mainau is operated by a limited liability company, Mainau GmbH. The island and all its properties were transferred to the company in 1974 by Lennart Count Bernadotte and his wife Sonja Countess Bernadotte, marking a significant milestone in the history of Mainau Island. Mainau GmbH employs 150 permanent staff and 30 trainees throughout the year, with a total of 400 people working there during the flower season from March to October. The park and gardens are open all year round. The GmbH's divisions are "Park, Garden and Forest," "Catering" and "Retail," as well as Marketing & Sales, Infrastructure, sustainability, organizational development, human resources, and communications. As a private company without public subsidies, Mainau GmbH operates according to market economy principles. The sole shareholder of Mainau GmbH is the Lennart Bernadotte Foundation, a non-profit foundation with legal capacity under civil law.
The Mainau management team
Björn Count Bernadotte
Born in 1975, the eldest son of Sonja and Lennart Bernadotte has been managing director of Mainau GmbH since 2011. Since 2025, he has been steering the company's fortunes together with Michael Roensch. Prior to this, he completed a commercial apprenticeship and studied social pedagogy in Rorschach (Switzerland). He not only applies the knowledge he acquired there to his work as managing director of Mainau GmbH, but also uses it in his role as managing director of the non-profit Lennart Bernadotte Foundation. Björn Graf Bernadotte lives in the baroque castle on the island of Mainau.
Michael Roensch
After successfully completing his business studies at Ravensburg University of Applied Sciences with a focus on tourism, 60-year-old Michael Roensch, originally from Überlingen, held various positions, initially in sales in the medical technology sector, including several years in Switzerland. In 2016, the position of managing director at the Romantik Hotel Kleber Post brought him back to Baden-Württemberg. From 2020 to July 2025, Michael Roensch was managing director of EPnP Medical GmbH. Michael Roensch has been a member of the Mainau management team since November 2025.