what to do with perennials in the fall

In the fall, it is common to cut back perennials that have started to turn brown and die back. However, some perennials should be left standing to protect new shoots through the winter, offer up important habitat for local wildlife, or provide height and interest through the winter months. Therefore, the decision to cut or not to cut depends on the type of perennial. For example, low-growing evergreen or semi-evergreen perennials should not be cut back in the fall. On the other hand, most herbaceous perennials die off above ground in the winter and sprout back up from the roots the next spring, so they can be cut back after several hard frosts. Some perennials, like garden mums, anise hyssop, red-hot poker, and Montauk daisy, should not be cut back in the fall because they are more likely to survive the cold of winter if their tops are left to collect leaves and snow for insulation and moisture. If perennials were diseased during the past season, their foliage should be cut all the way down to the ground and disposed of in an area far enough away from the garden that other plants won’t be subject to the disease.