As a professional landscape architect who specialized in planting design and her work included estates, wineries, and large scale residential gardens, as well as public, commercial, and educational projects.

In an interview with Margaret Schulze for NikkeiWest Mai recalled, “I spent much of my early life in boots stomping on particular tomatoes and collecting the seed for further crosses.”[2] Arbegast attended San Jose State College until 1942 when her family was evicted and sent to the Heart Mountain Relocation Center in Wyoming.

Arbegast played a key role in the gift of Blake Garden to the UC Berkeley Department of Landscape Architecture and was its first acting director after the transfer in 1957.

[5] Arbegast specialized in planting design and her work included estates, wineries, and large scale residential gardens, as well as public, commercial, and educational projects.

[6] Arbegast was involved in the community as a member and trustee of many boards and foundations including the University of California Botanical Garden, Filoli Center Founding Committee, Saratoga Horticulture Foundation, American Association of Botanic Gardens and Arboreta (AABGA), San Francisco Bay Conservation and Development Commission Design Review Board, and the Strybing Arboretum Society.

Well documented projects include the UC Davis Arboretum (1975–1977), Trefethen Vineyards (1976–1990), California Palace of the Legion of Honor renovation (1991–1995), and the Embarcadero Center (1992, 1996).