_Winter protection of plants._

If the ground is not ready for planting in the fall, or if it is desired for any reason to delay until spring, the trees or bushes may be heeled-in, as illustrated in Fig. 151. The roots are laid in a furrow or trench, and are covered with well-firmed earth. Straw or manure may be thrown over the earth still further to protect the roots, but if it is thrown over the tops, mice may be attracted by it and the trees be girdled. Tender trees or bushes may be lightly covered to the tips with earth. Plants should be heeled-in only in loose, warm, loamy or sandy ground and in a well-drained place.

Fall-planted trees should generally be mounded up, sometimes even as high as shown in Fig. 152. This hilling holds the plant in position, carries off the water, prevents too deep freezing, and holds the earth from heaving. The mound is taken away in the spring. It is sometimes advisable to mound-up established trees in the fall, but on well-drained land the practice is usually not necessary. In hilling trees, pains should be taken not to leave deep holes, from which the earth was dug, close to the tree, for water collects in them. Roses and many other bushes may be mounded in the fall with profit.

It is always advisable to mulch plants that are set in the fall. Any loose and dry material--as straw, manure, leaves, leafmold, litter from yards and stables, pine boughs--may be used for this purpose. Very strong or compact manures, as those in which there is little straw or litter, should be avoided. The ground may be covered to a depth of five or six inches, or even a foot or more if the material is loose. Avoid throwing strong manure directly on the crown of the plants, especially of herbs, for the materials that leach from the manure sometimes injure the crown buds and the roots.

This protection may also be given to established plants, particularly to those which, like roses and herbaceous plants, are expected to give a profusion of bloom the following year. This mulch affords not only winter protection, but is an efficient means of fertilizing the land. A large part of the plant-food materials have leached out of the mulch by spring, and have become incorporated in the soil, where the plant makes ready use of them.

Mulches also serve a most useful purpose in preventing the ground from packing and baking by the weight of snows and rains, and the cementing action of too much water in the surface soil. In the spring, the coarser parts of the mulch may be removed, and the finer parts spaded or hoed into the ground.

Tender bushes and small trees may be wrapped with straw, hay, burlaps, or pieces of matting or carpet. Even rather large trees, as bearing peach trees, are often baled up in this way, or sometimes with corn fodder, although the results in the protection of fruit-buds are not often very satisfactory. It is important that no grain is left in the baling material, else mice may be attracted to it. (The danger of gnawing by mice that nest in winter coverings is always to be anticipated.) It should be known, too, that the object in tying up or baling plants is not so much to protect from direct cold as to mitigate the effects of alternate freezing and thawing, and to protect from drying winds. Plants may be wrapped so thick and tight as to injure them.

The labor of protecting large plants is often great and the results uncertain, and in most cases it is a question whether more satisfaction could not be attained by growing only hardy trees and shrubs.

The objection to covering tender woody plants cannot be urged with equal force against tender herbs or very low bushes, for these are protected with ease. Even the ordinary mulch may afford sufficient protection; and if the tops kill back, the plant quickly renews itself from near the base, and in many plants--as in most hybrid perpetual roses--the best bloom is on these new growths of the season. Old boxes or barrels may be used to protect tender low plants (Figs. 153, 154). The box is filled with leaves or dry straw and either left open on top or covered with boards, boughs, or even with burlaps (Fig. 154).

Connoisseurs of tender roses and other plants sometimes go to the pains of erecting a collapsible shed over the bush, and filling with leaves or straw. Whether this is worth while depends wholly on the degree of satisfaction that one derives from the growing of choice plants (see _Roses,_ in Chap. VIII).

The tops of plants may be laid down for the winter. Figure 155 shows a method of laying down blackberries, as practiced in the Hudson River valley. The plants were tied to a trellis, as the method is in that country, two wires (_a, b_) having been run on either side of the row. The posts are hinged on a pivot to a short post (_c_), and are held in position by a brace (_d_). The entire trellis is then laid down on the approach of winter, as shown in the illustration. The blackberry tops are so strong that they hold the wires up from the ground, even when the trellis is laid down. To hold the wires close to the earth, stakes are thrust over them in a slanting position, as shown at _n n._ The snow that drifts through the plants ordinarily affords sufficient protection for plants which are as hardy as grapes and berries. In fact, the species may be uninjured even without cover, since, in their prostrate position, they escape the cold and drying winds.

In severe climates, or in the case of tender plants, the tops should be covered with straw, boughs, or litter, as recommended for regular mulch-covers. Sometimes a V-shaped trough made from two boards is placed over the stems of long or vine-like plants that have been laid down. All plants with slender or more or less pliant stems can be laid down with ease. With such protection, figs can be grown in the northern states. Peach and other fruit trees may be so trained as to be tipped over and covered.

Laid-down plants are often injured if the covering remains too late in the spring. The ground warms up early, and may start the buds on parts of the buried plants, and these tender buds may be broken when the plants are raised, or injured by sun, wind, or frost. The plants should be raised while the wood and buds are still hard and dormant.