As a result, the Cummers became wealthy and Nina was able to focus on her true interest of gardening. She gave lectures, wrote for gardening publications, and eventually became an expert on southern horticulture. She also hired the best landscape designers, including the Olmstead Brothers, to help create her private gardens. She was instrumental in establishing Memorial Park and founded the Florida Federation of Garden Clubs. In order to ensure that her passion for art, education, landscaping and gardening would continue she decided to bequeath the art collection and property to the city.