Answer: In general, leave the plants alone until frost nips back the tops. When the tops are brown and dry, trim them off. If the crown or some of the foliage seems evergreen, leave it alone. On some daylilies for instance, there is a showing of evergreen foliage, on others there is nothing showing for the winter. In the spring, tidy away any soft or brown foliage being careful not to damage emerging growth. Maintain several inches of mulch around the plants (but not overtop any visible crown) year round to help moderate soil temperatures and maintain soil moisture.
Your plants are hardy ones, but since they are in containers they may need extra winter protection for their roots. You might want to sink the containers in the ground to insulate the roots better, or perhaps surround them with mulch or another insulating material. If possible, protect them from wind, too.
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