A six-foot-high brick wall, built on the grounds of the New York Botanical Garden in the Bronx in the 1930s, encloses a secluded garden where one of the twentieth century's premier botanists, Arlow Stout, worked for more than thirty years. Each day during the summer, Stout would disappear through the wall's only gate to wade hip deep among hundreds of daylilies with tantalizing shades of yellow, red, and orange flowers. By crossing one particular plant with another, Stout deftly created plants that were unique – plants that were in the vanguard of a wave of daylily popularity that would rival the tulip craze of Europe 300 years before. Ever since the first tentative daylily crosses were made in the 1870s, amateur and professional breeders have developed more than 26 000 varieties from the original ten or so species of Hemerocallis. The qualities that separate the daylily from other garden plants are two-fold: first, their naturally occurring strains give breeders an unprecendented diversity of genetic material to work with. And second, the daylily is perhaps the easiest garden plant to grow and maintain. Where some plants require paragraphs of cultural directions, the daylily needs almost no instructions at all. It can be transplanted any time the garden is worked and into almost any type of soil. Overly wet or dry conditions don't seem to worry it, and in a world dependent on pesticides the daylily is virtually pest and disease-free. It grows rapidly and propagates itself so easily that in just a few years the thick foliage of the daylily chokes out any competing weeds. A display of daylilies is as close as most of us will ever come to a plant-it-and-forget-it garden.