Herbaceous perennials provide protection

The comfortably mild temperatures have helped make fall gardening chores rather enjoyable. As the gusty breezes continue to blow around fallen leaves, many gardeners are looking for outdoor jobs to prepare for the oncoming cold weather. So, if you just can not bring yourself to start the holiday shopping and are wanting to work outside, here are a few tips for preparing your perennial flower bed for winter.

In the past, you have probably been told to “clear cut” dead flowers during the fall to help control insect and disease problems. However, with herbaceous perennials that have been pest free, consider leaving them to provide structure, color, cold protection and wildlife habitat during the winter months.

For example, ornamental grasses can be attractive. Their long graceful blades flow freely in the winter winds. Likewise, a light snow gathers on the leaves to form a frozen fountain. Be cautious however. Plants near structures should be cut to the ground as they can pose a fire hazard.

Perennials with evergreen or semi-evergreen foliage also can provide interesting color. Foliage left on marginally hardy plants such as mums and tender ferns provides insulation and helps ensure overwintering of plant crowns. And seed heads of some plants, such as purple cone flowers and sunflowers, supply food for birds.

Of course, some perennials are naturally messy after dormancy and should be cut back in the fall. Trimmed materials should be added to the compost pile. If available, add some green material as well. The nitrogen source will help decompose the tough, woody stems.

Likewise, mulching is part of the winterizing process — particularly newly planted perennials. A thick layer of mulch helps prevent frost heaving in the winter. Small plants or newly planted plants are often pushed out of the ground by the freezing and thawing action of the soil. Keeping perennials covered with mulch keeps them frozen longer and helps keep them securely in place in the ground.

Finally, rose gardeners should not be in a big hurry to mulch this fall. Applying mulch now will do more harm than good. Warm temperatures have helped keep the soil warm, and that has slowed the normal cold acclimatization of these plants. Fall freezes will not harm the roses, so it is better to wait several weeks for the soil to freeze before applying your winter mulch protection.