green for only part of the winter, or only part of the foliage fully evergreen

Plant that retains most or some of its foliage throughout the year.

Retaining at least some green foliage well into the winter, or shedding leaves only in cold climates.

evergreen in its normal habitat, but liable to shed some or all of its leaves under rigorous conditions

A plant that drops its leaves in cold areas but keeps at least some of them in milder zones (typically zones 7~11).

By definition, a semi-evergreen daylily behaves like a dormant in the north but acts like an evergreen in mild, frost-free climates. Semi-evergreen daylilies theoretically perform reasonably well in both Southern and Northern gardens. In reality, however, the semi-evergreen classification may be considerably more complex. Semi-evergreen daylilies possess foliage that is slower to die back in the fall than that of dormant daylilies. Usually, a few green shoots, 2 to 4 inches tall, remain visible even after exposed to quite severe cold. These tips become mushy after successive freezes but, unlike evergreens, the main body of old foliage on semi-evergreen daylilies dies back completely in the winter. Although there is always new growth at the center of each foliage fan, it is not as persistent as it is in evergreens. Semi-evergreens are often quicker to re-emerge in the spring than are dormant daylilies.