An early amateur garden enthusiast, Ely developed an interest in garden design while spending summers with her husband at Meadowburn Farm in New York. She explored gardening with hardy perennial plants found in the agricultural landscape, a departure from the formal Victorian style that was in vogue. As word of her experiments with perennials spread, she became a source of information for fellow amateur gardeners. In 1903 she authored A Woman’s Hardy Garden, which became one of the most influential garden books in the United States at the time. As the first book to provide field-tested instructions on the design of the American perennial garden, the book was widely acclaimed by both the public and in reviews, including The New York Times. It was printed sixteen times before going out of print in the 1930s and helped popularize the design of perennial gardens and broaden interest in gardens and gardening. This resulted in extensive growth in amateur gardening especially by women and members of the upper and middle classes (who up until then had been restricted from physical labor by class boundaries), and helped lead to the growth of the landscape architecture profession in the first part of the century. A founding member of the Garden Club of America, Ely published two subsequent books, Another Hardy Garden Book (1905) and The Practical Flower Garden (1911).