In this case, the dead portion of the plant, the upper stalks, are removed, but the green basal growth is left intact. A pair of sharp hand pruners will allow you to get in close and do a neat job of cleaning up. But if time is short, to get the job done quickly, whack the tops off with hedge shears. Using a pair of garden shears, remove dead leaves and do just a tad of shaping if needed. When their flowers have faded, remove only the spent blooms.
Early spring is the time to shear the foliage back to the green growth at the base of the plant.
Shrubby perennial herbs, such as lavenders, santolina, sages and thymes, should be left intact over the winter. They are pruned back and shaped in spring, just as new growth begins to appear. In areas where I plan to seed in poppies and larkspur early in March, I cover the mulch with a mix of compost and garden soil. Yard art and containers, especially terra cotta, that may be damaged by frost are collected and stored away for the winter, along with stakes and tomato cages. I treat mine with Thompson's water seal every few years.