Manual of American Grape-Growing. U. P. Hedrick
frozen plants so that they are more injured than otherwise by rapid thawing. In locations near bodies of water, the best slope is toward the water, regardless of direction. The exposure may sometimes be selected to advantage with reference to the prevailing winds.
CHAPTER III
PROPAGATION
The grape commends itself to commercial and amateur growers alike by its ease of propagation. The vines of all species may be propagated from seed, and all but one of the several cultivated species may be grown readily from cuttings or layers. All yield to grafting of one kind or another. Seeds are planted only to produce new varieties. At one time stocks were grown from seed, but this practice has fallen into disrepute because of the great variations in the seedlings. Varieties on their own roots and stocks are for most part propagated from cuttings. In the production of stocks, the viticulturist sets the orchardist a good example, for there can be no question that all tree-fruits suffer from being grown on seedling stocks. The grape is a vigorous, self-assertive plant and once it is started, whether from seeds, cuttings or layers, seldom fails to grow.
Seedlings
Growing seedling grapes is the simplest of operations. The seeds are taken from the grapes at harvest time, after which they must pass through a resting period of a few months. At once or in a month or two, the seeds should be stratified in moist sand and stored in a cold place until spring, when they may be sown in flats or in the open ground; or seed may be sown in a well-prepared piece of garden land in the autumn. When planted in the open, autumn or spring, the seeds are put in at the depth of an inch, an inch or two apart and in rows convenient for cultivation. Subsequent care consists of cultivation if the seed are sown in garden rows, and in pricking out when true leaves appear if planted in flats. In ground that crusts, an expedient is to mix grape seed with apple seed; the apple seedlings, being more vigorous, break the crust and act as nurse plants to the more tender grapes. Sometimes it is helpful to the young plants to mulch the ground lightly with lawn clippings or moss. Grape seedlings grow rapidly, often making from two to three feet of wood in a season.
The young plants are thinned or set to stand four or five inches apart in the nursery row. At the end of the first season, all plants are cut back severely and almost entirely covered with earth by plowing up to the row on both sides. This earth, of course, is leveled the following spring. If the seasons are propitious and all goes well, the seedlings are ready for the vineyard at the end of the second season, but if for any reason they have fared badly during their first two years, it is much better to give them a third season in the nursery. Seedling vines are seldom as vigorous as those from cuttings, and unusual care must be taken in setting in the vineyard, though the operation is essentially the same as that to be described for vines from cuttings. The third season the vines are kept to a single shoot and are pinched back when the canes reach a length of five or six feet. In the autumn, they are pruned back to two or three feet. In the spring of the fourth season, the trellis is put up and a few fruits may be allowed to ripen.
The vines of promise may now be selected. The plants, however, must fruit twice or oftener before it can be told whether hopes are consummated or must be deferred. Growing seedlings for new varieties is a game full of chances in which, while there may be little immediate or individual gain, there is much pleasure. It is hardly too much to say that the grape industry of eastern America, with its 300,000 acres and 1500 varieties, betokens the good that has come from growing seedling grapes.
Dormant Cuttings
Vines for vineyards, with the exception of varieties of Rotundifolia, are propagated from cuttings of hard wood taken from the season's canes when the vines are pruned. The inactive buds in these cuttings may be brought into active growth, and roots induced to grow from the cut surfaces by various means. By this miracle of Nature, an infinite number of plants, in an endless procession, may be propagated from the product of a single seed, each plant complete in its heredity and differing from its fellows only in accordance with environment.
Time to make cuttings.
A good cutting should have a protective callus over the cut and this requires time, so that the sooner cuttings are made after the wood becomes thoroughly dormant the better. Besides, the cutting should use its stored food material for the formation of adventitious roots rather than have it pass into buds, as it quickly does late in the dormant season when buds are about to open. If cuttings must be made late in the season, transplanting must be delayed as long as possible, and the cuttings be set in a northerly aspect to prevent the premature development of the buds. However, the grape responds surprisingly well to the call of Nature in forming roots, and great importance need not be attached to the time at which the cuttings are made.
Selecting cutting wood.
Cuttings are made from one-year-old wood; that is, canes produced during the summer are taken for cuttings in the fall. Immature canes and those with soft, spongy wood ought not to be used. Strong vigorous canes should be given preference over weak growth, but most nurserymen maintain that very large canes do not make as good cuttings as do those of medium size, the objection to large size being that the cuttings do not root as well. Short-jointed wood is better than long-jointed. Cuttings from vines weakened by insects and fungi are liable to be weak, soft, immature and poorly stored with food. The wood should be smooth and straight.
Making the cutting.
Grape cuttings vary in length from four inches to two feet, the length depending on the climate and the soil of the nursery and the species and variety. The hotter and drier the climate and the lighter the soil, the longer the cutting needs to be. Six to nine inches, however, is the usual length in the climate of eastern America, while on the Pacific slope the length varies from eight to fifteen inches. For convenience in handling, all cuttings should be approximately of the same length, to insure which some kind of simple gauge is needed. Various gauges are used, as marks cut in the working table, a stick of the required length, or a cutting-box.
In making the cuttings, a slanting cut is made close below the lowest bud, while about an inch of wood is left above the upper bud. When possible, a heel of old wood is left at the lower end; or, still better, a whorl of buds, as roots usually start from each bud. The finished cuttings are tied in bundles, all butts one way, and are then ready to be heeled-in. This is done by burying in trenches, butts up, and covering with a few inches of soil. It is important to invert the cuttings in trenching, since otherwise the tops often start to grow before the butts are properly calloused, and it is very essential that the tops remain dormant until roots appear to support the new growth.
Cuttings are planted in the nursery in rows wide enough apart for cultivation and two or three inches apart in the row. Trenches are made with a plow; perpendicular if the cuttings are shorter, and a little slanting if longer than six inches. The cuttings are set at a depth which permits the upper buds to project above the ground, as shown in Fig. 6. When the cuttings in a row are placed, two inches of soil are put in and pressed firmly about the base of the cuttings. Then the trench is evenly filled with earth and the cultivator follows. Doing duty by the young plants consists in cultivating often during the summer to keep the soil moist and mellow.