The grape seldom suffers from hot weather in a grape region. The fruit is sometimes scalded in the full blaze of a hot sun, but the ample foliage of the vine usually furnishes protection against a burning sun. At maturing time, the heat of an unclouded sun, if the air circulates freely, insures a finely finished product. Deep planting helps to offset the harmful influences of warm climates.

_Humidity of summer weather._

The grape is very sensitive to moisture conditions, and grows best in regions where the summer rainfall is comparatively light. A damp and cloudy summer brings disaster to the vineyard in several ways; as small growth of vine, small set of fruit, a crop of poor quality, and the development of the several fungous diseases. Although the grape stands drought, a superfluity of moisture in the soil may do little harm, as is shown in irrigated vineyards, but a humid air is fatal to success especially if the air is both warm and wet. Moist weather during the time of maturity is particularly disastrous to the grape, as are frequent fogs. Cold wet weather in blooming time is the grape-grower's vernal bane, since it most effectually prevents the setting of fruit. It may be laid down as a rule that the grape lives by sunlight, warmth and air--it often thrives on the desert's edge.

These considerations make it manifest that the monthly and seasonal means of precipitation must be considered in selecting a locality to grow grapes.

_Spring and autumn frosts._

The average date at which the last killing frost occurs in the spring often determines the limit in lat.i.tude at which the grape can be grown. Even in the most favored grape region of the continent, killing frosts occasionally destroy the grape crop, and there are few seasons in which frost does not take some toll. Thus on May 7, 1916, frost all but ruined the crop of wine- and table-grapes in the great grape region of northern California where frosts are seldom expected in May.

Little or nothing can be done to protect grapes from frost. Windbreaks as often favor the frost as the vine, and smudging or heating the vineyards is too expensive to be practical. In growing grapes, therefore, the commonly recognized precaution of selecting a site near water, on slopes or in a warm thermal belt must be exercised.

The limits of grape culture are also determined by early autumn frosts. The grape stands two or three degrees of frost, but anything lower usually destroys the crop. Here, again, the only precaution is to take pains in selecting the site.

_The use of weather data and dates of life events of the grape._

These considerations of length of season, humidity and spring and fall frosts make it plain that the grape-grower must synchronize these phases of climate with the life events of the grape. In particular, he must study weather data in relation to the blooming and ripening of grapes. Usually, the necessary weather data may be secured from the nearest local weather bureau, while the date of blooming and ripening may be obtained from the state experiment stations in the states where the grape is an important crop.

_Winter temperature._

Varieties of native grapes are seldom injured in America by winter-killing, since they are usually planted in climates in which wild grapes withstand winter conditions. Native varieties follow the rule that plant and climate are truly congenial in regions in which the plant thrives without the aid of man. A few varieties of native grapes fare badly in the winter's cold of northern grape regions, and the tender Vinifera vine is at the mercy of the winter wherever the mercury goes below zero. In cold climates, therefore, care must be exercised in selecting hardy varieties and in following careful cultural methods with the tender sorts. If other climatic conditions are favorable, however, winter-killing is not an unsurmountable difficulty, since the grape is easily protected from cold, so easily that the tender Viniferas may be grown in the cold North with winter protection.

_Air currents._

Currents of air are of but local importance in growing tree-fruits, but are of general and vital importance in growing the grape. The direction, force and frequency of prevailing winds are often controlling factors in the suppression of fungous diseases of the grape, and the presence of fungi often means success or failure in regions in which the grape is planted. Winds are beneficial, too, when they bring warm air or dry air, and when they keep frosty air in motion. The air must move in all grape regions, whether from canon, mountain, lake or sea. Sunlight, warmth, and air in motion are life to the grape. Sometimes winds may be detrimental; as when too cold, too bl.u.s.tering, or when they bring hail, the latter being about the most disastrous of all natural calamities. Windbreaks are of small value and are often worse than useless. Having planted his vineyard, the grape-grower must take the winds as they blow.

_Soils for grapes_

A prime requisite for a vineyard being earth in which vines will grow, successful grape-growing is eminently dependent on the selection of soil. Many mistakes are made in the great grape regions in planting on unsuitable soils, the planter going on the a.s.sumption that any soil in a grape region should be good enough for the grape. But the crust of the earth in grape regions is not all grape soil. In New York, for example, much of the land in the three grape regions is better fitted for producing crops for the mason or road-mender than for the grape-grower. Other soils in these regions are fit for vineyards only when tiled, and tiling does not make all wet land fit for tilling.

Heavy, clammy clays, light sands, soils parched with thirst, thin or hungry soils--on all of these the grower may plant but will seldom harvest.

_The ideal soil._

Grapes may be well grown in a wide range of soils if the land is well drained, open to air and if it holds heat. But without these essentials, whatever the soil, all subsequent treatment fails to produce a good vineyard. Generally speaking, the grape grows best in a light, free-working, gravelly loam, but there are many good vineyards in gravelly or stony clays, gravel or stone to furnish drainage, let in the air and to hold heat. Contrary to general belief, the grape seldom thrives in very sandy soils unless there is a fair admixture of clay, considerable decomposing vegetable matter and a clay subsoil.

The latter, however, must not come too close to the surface. Some of the best vineyard lands in the country are very stony, the stones hindering only in making the land difficult to till. Nearly all grapes require a friable soil, compactness being a serious defect. Virgil, writing in Christ's time, gave good advice as to soil for the vine:

"A free loose earth is what the vines demand, Where wind and frost have help'd the lab'rer's hand, And st.u.r.dy peasants deep have stirr'd the land."

Cold, churlish, sticky or clammy clays are never to the liking of the grape.

Great fertility is not necessary in grape lands. Indeed, the grape is conspicuous among cultivated plants for ability to nourish itself where the food supply is scant. Soils naturally too rich produce an overgrowth of vine, the season's wood does not mature, the crop does not set, and the grapes lack sugar, size, color and flavor. Good physical condition and warmth in a well-watered, well-aired soil enable the grape to search far and wide for its food.

_Drainage._

No cultivated grape endures a wet soil; all demand drainage. A few sorts may thrive for a time in moist, heavy land, but more often they do not live though they may linger. The water-table should be at least two feet from the surface. If by chance this comes naturally, so much the better, but otherwise the land must be tile-drained. Sloping land is by no means always well drained, many hillsides having a subsoil so impervious or so retentive of moisture that under-drainage is a necessity. The texture of the land is usually improved so greatly by good drainage that the grower has little need to rely on the clemency of the season in carrying on vineyard cultivation in well-drained land.

_Soil adaptations._

In the refinement of viticulture, grape-growers find that particular varieties grow best in a particular soil, the likes and dislikes being determined only by trial, for the peculiarities which adapt a soil to a variety are not a.n.a.lyzable. Some varieties, on the other hand, the Concord being a good example, grow fruitfully in a great variety of soils. Each of the several species with their varieties has quite distinct adaptations to soils. This is taken advantage of in planting varieties on uncongenial soils after they have been grafted on a vine which finds itself at home in the particular soil. Much has been accomplished in growing varieties on uncongenial soils by consorting them with other stocks, an operation which has brought forth volumes of discussion as to the adaptabilities of cions to stocks and stocks to soils, subjects to receive attention on a later page.

_Insects and fungi_

The profitable grape regions of the country have all been established in regions comparatively free from grape insects and fungi. If pests came later in considerable numbers, the industry, in the old days, perished. Here and there in the agricultural regions of the country may be found a sorry company of halt and maimed vines, remnants of once flourishing vineyards, brought to their miserable condition by some scourge of insects or fungi. The advent of spraying and of better knowledge of the habits of the pests has greatly lessened the importance of parasites as a factor in determining the value of a region for grape-growing; but even in the light of the new knowledge, it is not wise to go against Nature in regions where pests are strongly intrenched.

_Commercial factors_

The dominant factors that lead to the planting of large areas to any one fruit are often economic ones; as transportation, markets, labor, facilities for making by-products, and opportunity to join in buying and selling organizations. All of these factors play an important part in determining the bounds of grape regions, but a lesser part than in the establishment of large areas of other fruits, for the reason that the grape is so largely grown for raisins, wine, champagne and grape-juice, products condensed in form, made with little labor, easily transported, which keep long and find ready market at any time.

Again, where natural conditions are favorable for grape-growing, the crop comes almost as a gift from Nature; whereas, if the grower must breast the blows of unfavorable natural circ.u.mstances, no matter how favorable the economic factors may be, the vineyard is seldom profitable. Natural factors, therefore, outweigh economic ones in grape-growing, but the latter must be considered in seeking a site for a vineyard, a task discussed under several heads to follow.

_Accessibility to markets._

Markets ought to be accessible in commercial grape-growing. A location in which there is a good local market, and at the same time ample facilities for shipping to distant markets, is desirable. If there are also opportunities to dispose of any surplus to makers of raisins, wine or grape-juice, the grower has well-nigh attained the ideal.

Further to be desired are good roads, short hauls, quick transportation, reasonable freight rates, refrigerator service and cooperative agencies. The more of these advantages a grower has at his disposal, the less likely he is to fail in commercial compet.i.tion.

_General_ versus _local markets._

The grower must be reminded rather than informed that he must decide in locating his vineyard whether he will grow for distant markets, for manufacturing into grape products, or for local markets. Determination to grow grapes once made, subsequent procedure at every step depends on the disposition to be made of the product. Summarized, the differences in growing grapes for the two markets are: For the general market: the acreage should be large; the market may be distant; the varieties few; the cost of production low; sales large and prices low; the dealings are with middlemen; and extensive culture is practiced.

For the local market: the acreage may be small; the market must be near and prices must be high; the sales are direct to the consumer; there must be succession in ripening; and intensive culture is practiced. For the general market, the vineyard is the unit; for the local market, the variety should be the unit. In this discussion, however, "large acreage" and "extensive culture" set against "small acreage" and "intensive culture" may mislead. This is a case in which a large endeavor may be a small endeavor, and a small endeavor a large one; or, in which it may be well to take the advice of Virgil, who advised Roman vineyardists, "Praise great estates; farm a small one."

The grape-growing of the times tends more and more to growing for general markets. The grower plants to skim a comparatively small return from a large area. This division of grape-growing is now well developed in America. Intensive grape-growing for local markets is not well developed. There are, however, many opportunities in America for easy triumphs in fruit-growing in the planting of vineyards for local markets. No other fruit responds to fine art in culture so well as the grape. Given choicely good varieties and a finely finished product, and the grower may have almost what he desires for the produce of his skill. With the grape, too, palm of merit goes with skill in culture; among all who grow plants, only the florist can rival the viticulturist in guiding the development of a plant to a special end.

In cultivating, fertilizing, training, grafting, pruning, spraying, in every cultural operation, the grape-grower has opportunities to sell his skill not given in so high degree to the grower of other fruits.

_Labor._

A great advantage in the congregation of vineyardists in grape regions is found when labor must be obtained. Skilled labor is required to cultivate the vine, and such labor can be freely secured only in centers of viticulture. Grape-growing is a specialists' business, and it takes more than a day or a season to make a vine-dresser out of a farmer, gardener or an orchardist. Expert labor is most easily obtained and is of best quality where grapes abound. Common labor must be somewhat abundant, also, in good vineyard locations, for such rush tasks as tying and picking. In these two operations, women, children or other unskilled labor may be employed to advantage. The grape harvest must often be hurried, and to keep it in full swing a near-by city from which to draw pickers is a great a.s.set.

_Vineyard sites._

Within a grape region, the site is important in determining where to plant. The site is the local position of the vineyard. Sites cannot be standardized, and therefore no two are alike. The cardinal natural factors to be secured in a site are warmth, sun, air and freedom from frost. These factors have been discussed in a general way under the climate of grape regions, but one needs to particularize a little more closely to ascertain how they affect individual vineyards. Warmth, sun, air and frostlessness are best secured by proximity to water, high land and proper exposure.

_Proximity to water._

The favorable influences of water are well ill.u.s.trated in the grape regions of New York, Pennsylvania, Ohio and Canada. All of the grape districts in these regions are bounded on one or more sides by water.

The equalizing effects of large bodies of water on temperature, warmer winter and cooler summer, are so well known as scarcely to need comment. Hardly less important than the effects of water on temperature are the off-sh.o.r.e breezes of night and the in-sh.o.r.e breezes of day which blow on large bodies of water. These keep the air of the vineyard in constant motion and so prevent frosts in spring and autumn, and also dry foliage and fruit so that spores of fungi have difficulty in finding foothold. But if water brings fogs, dews and humidity, as does the Pacific, grapes must be planted inland; otherwise leaf, bloom and fruit are born in the blight of fungi. The benign influences of water are felt in the eastern grape regions at distances of one to four miles, seldom farther. These narrow belts about the eastern waters are bounded on the landward side by high bluffs over which many showers fail to pa.s.s and which protect the belts below from heavy dews. Where the background of bluffs in these regions sinks to level land, vineyards cease.

Vineyards are usually some distance above the water, the range in alt.i.tude running from fifty to five hundred feet. Where the alt.i.tude is much higher, immunity to frosts and winter freezing ceases, for the reason that the atmosphere is rarer and drier so that heat radiates rapidly from the land. As the height increases, also, the revels of the wind play havoc with the vines. Yet, one is often surprised to find good vineyards at the level of the lakes or, on the other hand, crowning high hills. Alt.i.tude in grape-growing must, therefore, be determined by experiment. We know very little of the formation of the thermal belts on high land so favorable to the grape.

_The lay of the land._

We a.s.sociate the grape with rugged land; as the vines on the banks of the Rhine, the rolling lands of Burgundy, the slopes of Vesuvius and Olympus, the high hills of Madeira, the cloud-capped mountains of Teneriffe, mountain slopes in California and the escarpments of grape regions in eastern America. These examples prove how well adapted rolling lands, inclined plains and even steep and rocky hillsides are to the culture of the vine. Virgil long ago wrote, "Bacchus is partial to broad, sunny hills." Yet rolling lands are not essential to the culture of the grape, for in Europe and America very good grapes are grown on unsheltered plains, provided the land has an elevation on one or more boundaries above the surrounding country. If the conditions of soil and climate which the grape requires can be found on level land or moderate slopes, such situations are much better than steep declivities, since on these the cost of all vineyard operations is greater and heavy rains erode the soil. The soil on hills, too, is often scant and n.i.g.g.ardly. Level land, however, must not be shut in on all sides by higher land as untimely frost will often lay waste vines in such a situation.

_Exposures._

The exposure, or the slope of the land toward a point of the compa.s.s, is important in choosing a site for the vineyard, although the value of particular exposures is often exaggerated. Let it be remembered that good grapes may be grown in vineyards exposed to any point of the compa.s.s, but that slight advantages may sometimes come, depending on the particular environment of the plantation, and then solve the problem according to conditions. The following are theories as to exposure: A southern exposure is warmer and hence earlier than a northern, and is, therefore, the best slope for early grapes as well as for very late ones liable to be caught by frost. Northward and westward slopes r.e.t.a.r.d the leafing and blooming period, thus often enabling the grape to escape untimely spring frosts; though to plant on such slopes may be robbing Peter to pay Paul, as what is gained in r.e.t.a.r.dation in spring may be lost in the fall with the result that the vines may be caught by frost and may fail to ripen their crop. Frost damage is usually greatest on a bold eastern slope, and vines suffer most in winter freezes on this exposure, since the direct rays of the rising sun strike the 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.

[Ill.u.s.tration: PLATE II.--Fitting the land for planting.]