By far the most popular daylily, Stella de Oro is hardy in all zones and blooms profusely for months on end.  This award winning perennial features a dense clump of grassy green foliage with golden yellow trumpet like flowers from early summer into fall.  Choice for mass planting, edging, borders and boulvard plantings.  Trim back spent flower stalks, otherwise this selection is one of the most low-maintenence perennials.