Gardeners have long been accustomed to shielding their plants from insect and disease damage, but often neglect to supply protection from one of the greatest dangers - winter injury.

Of all garden plants, herbaceous perennials suffer the most from winter injury. Annuals have already scattered next year’s seed and shrubs have deeply anchored root systems, so they are safe. Perennials, on the other hand, are largely defenseless against the freezing, thawing and heaving which occurs during the cold months.

In areas where snow covers the ground from fall to spring, the task of “bedding down” is not so important. Borderline states which experience open winters also provide conditions that are disastrous for plant life. When nature does not offer a preventive snow blanket, the gardener must provide artificial protection.

The purpose of a winter cover is to keep plants frozen. Protective material should not be applied until the ground is solid, for if put on too soon, the cover may do more harm than good. No definite dates can be set, but the gardener must be alert to local conditions. In some years it may be as early as October and in others as late as December.

Whether old stalks and leaves should be removed before the roots are covered is a matter of dispute. Some maintain debris of the previous season aids in protecting the plant, while others claim it promotes diseases. I prefer to cut plants to four or five inches above ground. Ragged foliage is thus removed while enough stalk remains to hold straw, cranberry tops, evergreen branches or whatever else is used.

Cranberry tops or vines is one of the best materials for covering perennials. The tops can be used over a period of two or three years. Since cranberry tops and equally good marsh grass are restricted in availability, evergreen branches can be used as well. Resourceful gardeners can go shopping for evergreen trees after Christmas and either cut them up or use them whole. Delaying winter covering until Christmas also assures that the ground will be frozen.

The materials mentioned are all light and airy, not to be said for leaves of common shade trees which mat when wet. A light sprinkling of leaves underneath the evergreen boughs can be used safely as extra protection, but a heavy cover will rot rather than protect your plants.

Perennials susceptible to decay at the crown require additional winter protection. Delphinium losses arc largely due to this and can be curtailed by first making a well-drained bed or by mounting a small amount of sifted coal ashes over the crown.

The wise gardener selects a cover that is readily available and neat in appearance. He avoids materials that become wet and soggy, having patience to apply the cover when the ground is frozen solid.