Answer: Perennial herbs are hardy and relatively low maintenance. The ones you have listed all fit this category, so there should be no special procedures to follow. After frost, trim away any browned and dead stems and mulch lightly around, but not over, the plants. Snow acts as an insulator and protects plants from excessive cold, so it is not something to worry about. In fact, plants tend to fare better when snow stays in place all winter. In the spring, tidy up any winter damage and gradually pull off debris that has blown in and become wedged in the plants.
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