Select plants with handsome foliage. 'Dixie Hummingbird' has handsome, strappy leaves in scale with the rest of the plant so it adds to the plant's overall appearance.
Foliage should look attractive — Now, take a closer look at the foliage. Does it add or detract from the all-over effect? Daylily foliage appears in early spring and lasts for months before the flowers bloom, so it had better earn its keep. After flowering, all daylily foliage goes through a ratty phase, but it can be cut back by half, and soon new leaves will replace the old. Finally, study the foliage-to-scape ratio. Are the flowers held well above the leaves, or are they trapped among them?
Foliage types are clues to a daylily's hardiness — Daylily foliage is categorized by its winter behavior in these three types: dormant, evergreen, and semievergreen.
Dormant foliage dies to the ground at the onset of winter, the plants form resting buds at the crown and, in spring, send forth new leaves. On the whole, cultivars with dormant foliage are the most cold tolerant. Evergreens are the least cold tolerant—they do not form resting buds and, in warm climates, produce leaves all year. But hardy evergreens—and there are a good many of these—behave like dormants when grown in the North. In winter, their foliage dies to the ground. Daylilies with semievergreen foliage tend to retain their leaves in the South and lose them in the North.
As the breeding of daylilies has become increasingly complex, the lines of foliage type have become blurred. So has the hardiness issue. But, in general, Northern gardeners ordering from catalogs would do well to stick to dormant daylilies. Southern gardeners have a greater choice--evergreens or semievergreens. Some dormant daylilies do well in the South, but many pine for their cold requirement, dwindle, and eventually die in a too-warm climate. The only foolproof way to select the daylilies for your climate is to make your choices at a local display garden or nursery.
Tetraploids are not necessarily better garden plants -- Catalogs offer first-time daylily buyers another baffling choice--diploids or tetraploids. Diploids have two sets of chromosomes in each cell nucleus, and tetraploids have four. To a hybridizer, the tetraploid's extra genetic material increases the possibility for creating blossoms with new colors and forms. "Tets" also tend to produce larger flowers, and the substance of both flower and foliage is usually heavier. But, as a gardener, it doesn't matter whether you grow "dips" or "tets." In many cases, you would be hard put to tell the difference. Personal preference, not the chromosome count, should be a gardener's guide to a good daylily.